A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. NIST. Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') -Wnull-dereference. Explicitly initialize all your variables and other data stores, either during declaration or just before the first usage. When it comes to these specific properties, you're safe. Is this from a fortify web scan, or from a static code analysis? rev2023.3.3.43278. ASCRM-CWE-252-resource. operator is the logical negation operator. Here is a code snippet: getAuth() should not return null. cmd=cmd.trim(); Null-pointer dereference issues can occur through a number of flaws, Unless otherwise specified, all content on the site is Creative Commons Attribution-ShareAlike v4.0 and provided without warranty of service or accuracy. "The Art of Software Security Assessment". To subscribe to this RSS feed, copy and paste this URL into your RSS reader. will be valuable in planning subsequent attacks. process, unless exception handling (on some platforms) is invoked, and Copyright 2023, OWASP Foundation, Inc. instructions how to enable JavaScript in your web browser. "24 Deadly Sins of Software Security". This table shows the weaknesses and high level categories that are related to this weakness. The same occurs with the presence of every form in html/jsp (x)/asp (x) page, that are suspect of CSRF weakness. Wij hebben geen controle over de inhoud van deze sites. SSL software allows remote attackers to cause a denial of service (crash) via a crafted SSL/TLS handshake that triggers a null dereference. They will always result in the crash of the It is important to remember here to return the literal and not the char being checked. It serves as a common language, a measuring stick for security tools, and as a baseline for weakness identification, mitigation, and prevention efforts. More information is available Please select a different filter. CWE is sponsored by the U.S. Department of Homeland Security (DHS) Cybersecurity and Infrastructure Security Agency (CISA) and managed by the Homeland Security Systems Engineering and Development Institute (HSSEDI) which is operated by The MITRE Corporation (MITRE). How do I convert a String to an int in Java? The SAST tool used was Fortify SCA, (and obviously if httpInputStream is different from null, to avoid a possible Null Dereference by invoking the close() method). Warn if the compiler detects paths that trigger erroneous or undefined behavior due to dereferencing a null pointer. Il suffit de nous contacter ! Fortify keeps track of the parts that came from the original input. In the following example, it is possible to request that memcpy move a much larger segment of memory than assumed: If returnChunkSize() happens to encounter an error it will return -1. The choice could be made to use a language that is not susceptible to these issues. Take the following code: Integer num; num = new Integer(10); of Computer Science University of Maryland College Park, MD ayewah@cs.umd.edu William Pugh Dept. Base - a weakness Note that this code is also vulnerable to a buffer overflow (CWE-119). Microsoft Press. Removed issues. How can we prove that the supernatural or paranormal doesn't exist? A force de persvrance et de courage, la petite fourmi finit par arriver au sommet de la montagne. Is Java "pass-by-reference" or "pass-by-value"? Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. The program can dereference a null-pointer because it does not check the return value of a function that might return null. how to fix null dereference in java fortify how to fix null dereference in java fortify . The lack of a null terminator in buf can result in a buffer overflow in the subsequent call to strcpy(). Synopsys-sigcoverity-common-api A challenge mostly of GitHub. In this case, the caller abuses the callee API by making certain assumptions about its behavior (that the return value can be used for authentication purposes). Dereference before null check (REVERSE_INULL) There may be a null pointer exception, or else the comparison against null is unnecessary. Category:Code Quality The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup. logic or to cause the application to reveal debugging information that Null Dereference Analysis in Practice Nathaniel Ayewah Dept. 2010. This table specifies different individual consequences associated with the weakness. OWASP, the OWASP logo, and Global AppSec are registered trademarks and AppSec Days, AppSec California, AppSec Cali, SnowFROC, and LASCON are trademarks of the OWASP Foundation, Inc. CODETOOLS-7900081 Fortify: Analize and fix "Null Dereference" issues. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. LKML Archive on lore.kernel.org help / color / mirror / Atom feed * [PATCH] dm: fix dax_dev NULL dereference @ 2019-07-30 11:37 Pankaj Gupta 2019-07-30 11:38 ` Pankaj Gupta 0 siblings, 1 reply; 7+ messages in thread From: Pankaj Gupta @ 2019-07-30 11:37 UTC (permalink / raw) To: snitzer, dan.j.williams Cc: dm-devel, linux-nvdimm, linux-fsdevel, linux-kernel, agk, pagupta 'Murphy Zhou' reports . [REF-44] Michael Howard, David LeBlanc It is impossible for the program to perform a graceful exit if required. TRESPASSING! The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup. Veracode's dynamic analysis scan automates the process, returning detailed guidance on security flaws to help developers fix them for good. null dereference fortify fix java Follow us. 1st Edition. When you assign the value of 10 on the second line, your value of 10 is written into the memory location referred to by x. case " Null Dereference ": return 476; // Fortify reports weak randomness issues under Obsolete by ESAPI, rather than in // the Insecure Randomness category if it thinks you are using ESAPI. The program might dereference a null-pointer because it does not check the return value of a function that might return null. 2019-07-15. If an attacker provides an address that appears to be well-formed, but the address does not resolve to a hostname, then the call to gethostbyaddr() will return NULL. Once you are fixing issues automatically (not all issues will be like this, so focus on certain always-true positives with standardized remediation that can be code generated through high-fidelity qualities), then you can turn your attention towards trivial true positives. Network monitor allows remote attackers to cause a denial of service (crash) via a malformed Q.931, which triggers a null dereference. Null-pointer dereferences, while common, can generally be found and corrected in a simple way. Ignoring a method's return value can cause the program to overlook unexpected states and conditions. Could someone advise here? Network Operations Management (NNM and Network Automation). There is no guarantee that the amount of data returned is equal to the amount of data requested. Connection String Parameter Pollution. Note that this code is also vulnerable to a buffer overflow . getAuth() should not return null.A method returning a List should per convention never return null but an empty List as default "empty" value.. private List getAuth(){ return new ArrayList<>(); } java.util.Collections.emptyList() should only be used, if you are sure that every caller of the method does not change the list (does not try to add any items), as this case " Null Dereference ": return 476; // Fortify reports weak randomness issues under Obsolete by ESAPI, rather than in // the Insecure Randomness category if it thinks you are using ESAPI. If an attacker can control the program's environment so that "cmd" is not defined, the program throws a NULL pointer exception when it attempts to call the trim() method. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. Theres still some work to be done. 2005-11-07. Apple. Java/JSP. Certain versions of content ("Material") accessible here may contain branding from Hewlett-Packard Company (now HP Inc.) and Hewlett Packard Enterprise Company. Connect and share knowledge within a single location that is structured and easy to search. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. Thanks for the input! The program can potentially dereference a null-pointer, thereby causing a segmentation fault. This behavior makes it important for programmers to examine the return value from read() and other IO methods to ensure that they receive the amount of data they expect. 2. Is a PhD visitor considered as a visiting scholar? "Automated Source Code Reliability Measure (ASCRM)". Furthermore, if the end of the file is reached before any characters are read, fgets() returns without writing anything to buf. The modules cover the full breadth and depth of topics for PCI Section 6.5 compliance and the items that are important for secure software development. [REF-961] Object Management Group (OMG). I'm using "HP Fortify v3.50" on a java project and I find lots of false positive on "Null Dereference", because Fortify doesn't see the control against null is in another method. Most errors and unusual events in Java result in an exception being thrown. Expressions (EXP), SEI CERT C Coding Standard - Guidelines 12. Network monitor allows remote attackers to cause a denial of service (crash) via a malformed RADIUS packet that triggers a null dereference. Fortify SCA is used to find and fix following software vulnerabilities at the root cause: Buffer Overflow, Command Injection, Cross-Site Scripting, Denial of Service, Format String, Integer Overflow, . sanity-checked previous to use, nearly all null-pointer dereferences The following function attempts to acquire a lock in order to perform operations on a shared resource. Base - a weakness Game allows remote attackers to cause a denial of service (server crash) via a missing argument, which triggers a null pointer dereference. In this tutorial, we'll take a look at the need to check for null in Java and various alternatives that . 2012-09-11. For Benchmark, we've seen it report it both ways. The following code shows a system property that is set to null and later dereferenced by a programmer who mistakenly assumes it will always be defined. How do I read / convert an InputStream into a String in Java? <, [REF-18] Secure Software, Inc.. "The CLASP Application Security Process". Closed. a property named cmd defined. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. If an attacker can create a smaller file, the program will recycle the remainder of the data from the previous user and treat it as though it belongs to the attacker. If you are working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the if statement; and unlock when it has finished. Just about every serious attack on a software system begins with the violation of a programmer's assumptions. NULL pointer dereferences are frequently resultant from rarely encountered error conditions, since these are most likely to escape detection during the testing phases. This information is often useful in understanding where a weakness fits within the context of external information sources. Making statements based on opinion; back them up with references or personal experience. occur. As a matter of fact, any miss in dealing with null cannot be identified at compile time and results in a NullPointerException at runtime.. Here is a code snippet: public class Example { private Collection<Auth> Authorities; public Example (SomeUser user) { for (String role: user.getAuth ()) { //This is where Fortify gives me a null dereference Authorities.add (new Auth (role)); } } private List<String> getAuth () { return null; } } java fortify Share Improve this question John Aldridge Hillsborough Nc Obituary, steps will go a long way to ensure that null-pointer dereferences do not These classes simply add the small amount of data to the return buffer, and set the return value to the number of bytes or characters read. What fortify do not like is the fact that you initialize the variable with null first, without condition, and then change it. CODETOOLS-7900078 Fortify: Analize and fix "Redundant Null Check" issues. This can cause DoDangerousOperation() to operate on an unexpected value. "Security problems caused by dereferencing null . About an argument in Famine, Affluence and Morality. The traditional defense of this coding error is: "If my program runs out of memory, it will fail. Most appsec missions are graded on fixing app vulns, not finding them. Redundant Null Check. Avoid Returning null from Methods. CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): Many analysis techniques have been proposed to determine when a potentially null value may be dereferenced. The Null dereference error was on the line of code sortName = lastName; not the call of the setter : fortify do not want you to conditionnally change the value of a variable that was set to null without doing so in all the branches. a NullPointerException. Revolution Radio With Scott Mckay, If you can guaranty this, then the empty List is even better, as it does not create a new object all the time. Not the answer you're looking for? Deerlake Middle School Teachers, Since the code does not check the return value from gethostbyaddr (CWE-252), a NULL pointer dereference (CWE-476) would then occur in the call to strcpy(). Thank you for visiting OWASP.org. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource. 2016-01. The different Modes of Introduction provide information about how and when this weakness may be introduced. Not the answer you're looking for? The The play-webgoat repository contains an example web app that uses the Play framework. Addison Wesley. There are some Fortify links at the end of the article for your reference. The Phase identifies a point in the life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase. <. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The best way to fix this is not returning, @MarkRotteveel those are from different classes, is there a way to return an empty list that will not cause null dereference? From a user's perspective that often manifests itself as poor usability. "Seven Pernicious Kingdoms: A Taxonomy of Software Security Errors". In .NET, it is not uncommon for programmers to misunderstand Read() and related methods that are part of many System.IO classes. How can I find out which sectors are used by files on NTFS? CWE, CWSS, CWRAF, and the CWE logo are trademarks of The MITRE Corporation. This Android application has registered to handle a URL when sent an intent: The application assumes the URL will always be included in the intent. Null-pointer errors are usually the result of one or more programmer assumptions being violated. The code loops through a set of users, reading a private data file for each user. Pour adhrer l'association, rien de plus simple : une cotisation minimale de 1,50 est demande. When the URL is not present, the call to getStringExtra() will return null, thus causing a null pointer exception when length() is called. The NULL pointer dereference weakness occurs where application dereferences a pointer that is expected to be a valid address but instead is equal to NULL. A method returning a List should per convention never return null but an empty List as default "empty" value. I'll update as soon as I have more information thx Thierry. Het is gebruikers verboden materiaal te plaatsen waarop personen jonger dan 18 jaar worden afgebeeld. More specific than a Base weakness. 2006. The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions. Instead use String.valueOf (object). What is the difference between public, protected, package-private and private in Java? What's the difference between a power rail and a signal line? Monitor the software for any unexpected behavior. Take the following code: Integer num; num = new Integer(10); However, its // behavior isn't consistent. All rights reserved. Unfortunately our Fortify scan takes several hours to run. The program can dereference a null-pointer because it does not check the return value of a function that might return null. CWE is sponsored by the U.S. Department of Homeland Security (DHS) Cybersecurity and Infrastructure Security Agency (CISA) and managed by the Homeland Security Systems Engineering and Development Institute (HSSEDI) which is operated by The MITRE Corporation (MITRE). When this happens, CWE refers to X as "primary" to Y, and Y is "resultant" from X. Network monitor allows remote attackers to cause a denial of service (crash) or execute arbitrary code via malformed packets that cause a NULL pointer dereference. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. As of September 1, 2017, the Material is now offered by Micro Focus, a separately owned and operated company. <, [REF-1031] "Null pointer / Null dereferencing". 2016-01. 3.7. Wikipedia. Dynamic analysis is a great way to uncover error-handling flaws. Show activity on this post. PS: Yes, Fortify should know that these properties are secure. In the following code, the programmer assumes that the system always has a property named "cmd" defined. (Generated from version 2022.4.0.0009 of the Fortify Secure Coding Rulepacks), Fortify Taxonomy: Software Security Errors. if statement; and unlock when it has finished. can be prevented. Fortify Software in partnership with FindBugs has launched the Java Open Review (JOR) Project. In order to avoid data races, correctly written programs must check the result of thread synchronization functions and appropriately handle all errors, either by attempting to recover from them or reporting them to higher levels. 2nd Edition. For an attacker it provides an opportunity to stress the system in unexpected ways. An unexpected return value could place the system in a state that could lead to a crash or other unintended behaviors. Poor code quality leads to unpredictable behavior. Cookie Security. Implementation: Proper sanity checks at implementation time can Follows a very simple code sample that should reproduce the issue: In this simple excerpt Fortify complains that "typedObj" can be null in the return statement. This also passes Fortify's scan: Thanks for contributing an answer to Stack Overflow! We recently migrated our community to a new web platform and regretably the content for this page needed to be programmatically ported from its previous wiki page. [A-Z a-z 0-9]*$")){ throw new IllegalArgumentException(); } message.setSubject(subject) This still gets flagged by Fortify. The platform is listed along with how frequently the given weakness appears for that instance. Thierry's answer works great. Team Collaboration and Endpoint Management. Suppress the warning (if Fortify allows that). The unary prefix ! Why are non-Western countries siding with China in the UN? -Wnull-dereference. This way you initialize sortName only once, and explicitely show that a null value is the right one in some cases, and not that you forgot some cases, leading to a var staying null while it is unexpected. The ftrace implementation in the Linux kernel before 3.8.8 allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact by leveraging the CAP_SYS_ADMIN capability for write access to the (1) set_ftrace_pid or (2) set_graph_function file, and then making an lseek system call. that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? Generally, null variables, references and collections are tricky to handle in Java code.They are not only hard to identify but also complex to deal with. <. Two common programmer assumptions are "this function call can never fail" and "it doesn't matter if this function call fails". Real ghetto African girls smoking with their pussies. It works under 64-bit systems in Windows, Linux and macOS environments, and can analyze source code intended for 32-bit, 64-bit and embedded ARM platforms. These classes simply add the small amount of data to the return buffer, and set the return value to the number of bytes or characters read. Alle rechten voorbehouden. including race conditions and simple programming omissions. Harvest Property Management Lodi, Ca, Anything that requires dynamic memory should be buried inside an RAII object that releases the memory when it goes out of scope. This code will definitely crash due to a null pointer dereference in certain cases. View Defect : wazuh/ossec-wazuh: USE_AFTER_FREE: C/C++: Coverity's suggestion to fix this bug is to use a delete[] deallocator, but the concerned file is in Null Dereference. Only iterating over the list would be fine. CWE, CWSS, CWRAF, and the CWE logo are trademarks of The MITRE Corporation. Browse other questions tagged java fortify or ask your own question. To learn more, see our tips on writing great answers. McGraw-Hill. If you preorder a special airline meal (e.g. There are at least three flavors of this problem: check-after-dereference, dereference-after-check, and dereference-after-store. Web-application scanning, also known as dynamic analysis, is a type of test that runs while an application is in a development environment. clones. Follows a very simple code sample that should reproduce the issue: public override bool Equals (object obj) { var typedObj = obj as SomeCustomClass; if (typedObj == null) return false; return this.Name == typedObj.Name; } In this simple excerpt Fortify complains that "typedObj" can be null in the return statement. Added Fortify's analysis trace, which is showing that the dereference of sortName is the problem. is incorrect. If an attacker can control the programs even then, little can be done to salvage the process. Fix : Analysis found that this is a false positive result; no code changes are required. Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. attacker might be able to use the resulting exception to bypass security are no complete fixes aside from contentious programming, the following Redundant Null Check. When to use LinkedList over ArrayList in Java? rev2023.3.3.43278. How do I generate random integers within a specific range in Java? More specific than a Pillar Weakness, but more general than a Base Weakness. If the program is performing an atomic operation, it can leave the system in an inconsistent state. But we have observed in practice that not every potential null dereference is a "bug " that developers want to fix. What video game is Charlie playing in Poker Face S01E07? Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, what happens if, just for testing, you do. <, [REF-1032] "Null Reference Creation and Null Pointer Dereference". Share Improve this answer Follow edited Jun 4, 2019 at 17:08 answered Jun 4, 2019 at 17:01 Thierry 5,170 33 39 vegan) just to try it, does this inconvenience the caterers and staff? Null-pointer dereferences, while common, can generally be found and The Null dereference error was on the line of code sortName = lastName; not the call of the setter : fortify do not want you to conditionnally change the value of a variable that was set to null without doing so in all the branches. The stream and reader classes do not consider it to be unusual or exceptional if only a small amount of data becomes available. But, when you try to declare a reference type, something different happens. Did the call to malloc() fail because req_size was too large or because there were too many requests being handled at the same time? Just about every serious attack on a software system begins with the violation of a programmer's assumptions. Find centralized, trusted content and collaborate around the technologies you use most. The method isXML () in jquery-1.4.4.js can dereference a null pointer on line 4283, thereby raising a NullExcpetion. This user is already logged in to another session. Expressions (EXP), Weaknesses in the 2019 CWE Top 25 Most Dangerous Software Errors, Weaknesses in the 2021 CWE Top 25 Most Dangerous Software Weaknesses, Weaknesses in the 2020 CWE Top 25 Most Dangerous Software Weaknesses, Weaknesses in the 2022 CWE Top 25 Most Dangerous Software Weaknesses, https://samate.nist.gov/SSATTM_Content/papers/Seven%20Pernicious%20Kingdoms%20-%20Taxonomy%20of%20Sw%20Security%20Errors%20-%20Tsipenyuk%20-%20Chess%20-%20McGraw.pdf, https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf, https://en.wikipedia.org/wiki/Null_pointer#Null_dereferencing, https://developer.apple.com/documentation/code_diagnostics/undefined_behavior_sanitizer/null_reference_creation_and_null_pointer_dereference, https://www.immuniweb.com/vulnerability/null-pointer-dereference.html, Cybersecurity and Infrastructure Security Agency, Homeland Security Systems Engineering and Development Institute, Null Dereference (Null Pointer Dereference), updated Applicable_Platforms, Common_Consequences, Relationships, Other_Notes, Taxonomy_Mappings, Weakness_Ordinalities, updated Common_Consequences, Demonstrative_Examples, Other_Notes, Potential_Mitigations, Weakness_Ordinalities, updated Potential_Mitigations, Relationships, updated Demonstrative_Examples, Description, Detection_Factors, Potential_Mitigations, updated Demonstrative_Examples, Observed_Examples, Relationships, updated Related_Attack_Patterns, Relationships, updated Observed_Examples, Related_Attack_Patterns, Relationships, updated Relationships, Taxonomy_Mappings, White_Box_Definitions, updated Demonstrative_Examples, Observed_Examples, updated Alternate_Terms, Applicable_Platforms, Observed_Examples.