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. Explanation Null-pointer errors are usually the result of one or more programmer assumptions being violated. Closed. As of September 1, 2017, the Material is now offered by Micro Focus, a separately owned and operated company. What I mean is, you must remember to set the pointer to NULL or it won't work. Through community-led open-source software projects, hundreds of local chapters worldwide, tens of thousands of members, and leading educational and training conferences, the OWASP Foundation is the source for . If you use any of the original input, you may still get the error. The SAST tool used was Fortify SCA, . Whenever we use the "return early" code pattern, Fortify is not able to understand it and raises a "possible null dereference" warning. Sorry I do not know how to make sense of the Rule ID you mentioned. References As // such, we are adding this other way to determine if . Null dereference is a common type of runtime failure in Java programs, and it is necessary to verify whether a dereference in the program is safe. The Open Web Application Security Project (OWASP) is a nonprofit foundation that works to improve the security of software. Linux reduced time to fix new defects, found by Coverity Scan, from 120 days to 5 days. The project is a simple C# console application, with no reference whatsoever to ASP.NET libraries. Notice how that can never be possible since the method returns early with a 'false' value on the previous 'if' statement. Could someone advise here? Null Dereference C/C++ C#/VB.NET/ASP.NET Java/JSP Abstract clones. #icon5632{font-size:;background:;padding:;border-radius:;color:;} Is it correct to use "the" before "materials used in making buildings are"? Java/JSP. The main theme of Dereferencing is placing the memory address into the reference. Investigate instances where Fortify has identified a null pointer as a potential security flaw. If maybeNull is null, the conditional will resolve to false, and will not enter the block where maybeNull.OtherMember is accessed. But I do see a problem in line 9: Thanks, you are correct, I meant line 9 and I see the error now. Primitive [byte, char, short, int, long, float, double, boolean]. The issues include: "Buffer Overflows," "Cross-Site Scripting" attacks, "SQL Injection," and many others. It has no particular knowledge of 83 // the Apache Commons null-checking method. In this paper we discuss some of the challenges of using a null dereference analysis in practice, and reasons why developers may not feel it necessary to change code to prevent ever possible null dereference. The Java VM sets them so, as long as Java isn't corrupted, you're safe. #icon5632:hover{color:;background:;} 180 Canada Larga Rd. Try this: if (connection != null && conection.State != ConnectionState.Closed) { conection.Close (); } But better, use a using block around your connection creation so it is automatically closed and disposed when it goes out of scope. The Java VM sets them so, as long as Java isn't corrupted, you're safe. Teams. Asking for help, clarification, or responding to other answers. Already on GitHub? Certain versions of content ("Material") accessible here may contain branding from Hewlett-Packard Company (now HP Inc.) and Hewlett Packard Enterprise Company. In Dungeon World, is the Bard's Arcane Art subject to the same failure outcomes as other spells? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. I did not try that. In the most recent project scanned, only 1 of 24 Null Dereference issues found was legitamite. "Leadership is nature's way of removing morons from the productive flow" - Dogbert Articles by Winston can be found here. If you have a method that should sometimes not return a value, you could return an empty Collection, or an Optional, which is new in Java 8. Note that this code is also vulnerable to a buffer overflow . Missing Check against Null. Wait hold on what is dereference now?. Well occasionally send you account related emails. "The good news about computers is that they do what you tell them to do. This type of 'return early' pattern is very common with validation as it avoids nested scopes thus making the code easier to read in general. So it seems highly unlikely that the line of code you've posted is the source of the exception. Even if you were to add input filtering, the odds are low that Fortify were to recognize it and stop producing the issue. Chain: The return value of a function returning a pointer is not checked for success ( CWE-252) resulting in the later use of an uninitialized variable ( CWE-456) and a null pointer dereference ( CWE-476) CVE-2007-3798. Null pointer dereference (NPD) is a widespread vulnerability that occurs whenever an executing program attempts to dereference a null pointer. I know we could change the code to remove it, but that would be changing the structure of our code because of a problem in the tool. This could allow the server to make the client crash due to the NULL pointer dereference Separate licenses are available for C/C++ analysis and Java analysis. Explanation. 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. NullPointerException is a runtime condition where we try to access or modify an object which has not been initialized yet. Team Collaboration and Endpoint Management, We are a .Net shop that recently re-started using Fortify Static Code Analyzer (have version 17.10.0156.). As a counter-example, though, note that calling free() or delete on a NULL in C and C++ is guaranteed to be a no-op. . The . This release, developed in Java technology, contains ESM Phase 3 development and upgrade efforts. Most null-pointer issues result in general software reliability problems, but if an attacker can intentionally trigger a null-pointer dereference, the attacker may be able to use the resulting exception to bypass security logic or to cause the application to reveal debugging information Also, the term 'pointer' is bad (but maybe it comes from the FindBugs tool): Java doesn't have pointers, it has references. So one cannot do Primitive.something(). Network Operations Management (NNM and Network Automation). I've been searching for an explanation of this message and can't find anything that clearly explains it. 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. application of binomial distribution in civil engineering Fix : Analysis found that this is a false positive result; no code changes are required. In this episode we look at 3 common ways to get - and then prevent - the "Attempt to dereference a null object" apex error**Our new course Astronomical Apex . In this example, the variable x is an int and Java will initialize it to 0 for you. Explanation Just about every serious attack on a software system begins with the violation of a programmer's assumptions. It essentially means that the object's reference variable is not pointing anywhere and refers to nothing or 'null'. Explanation Null-pointer errors are usually the result of one or more programmer assumptions being violated. If you get an exception, don't catch it and return null, instead wrap and rethrow the exception. Does it just mean failing to correctly check if a value is null? Thanks for contributing an answer to Information Security Stack Exchange! Insecure randomness errors occur when a function that can produce predictable values is used as a source of randomness in security-sensitive context. How can I reduce false positives and maintain the rule? The main theme of Dereferencing is placing the memory address into the reference. Palash Sachan 8-Feb-17 13:41pm. Team Collaboration and Endpoint Management. I believe this particular behavior is a gap in the Fortify analyzer implementation, as all other static analysis tools seem to understand the code flow and will not complain about potential null references in this case. relevant defects identified by Prevent were related to potential null dereference. Null Dereference Object Model Violation: Just one of equals() and hashCode() Defined Dead Code: Unused Field As we already know that "what is a pointer", a pointer is a variable that stores the address of another variable.The dereference operator is also known as an indirection operator, which is represented by (*). The root cause of each defect is clearly explained, making it easy to fix bugs Integrated with However, one article [1] claims that the cost of a one year license is based on the number of lines of code, regardless of the number of users. Board while may produce spurious "null dereference" reports. Null-pointer errors are usually the result of one or more programmer assumptions being violated. Demos (FindBugs, Fortify SCA) Integrating static analysis Wrap up. Try this: Copy Code if (connection != null && conection.State != ConnectionState.Closed) { conection.Close (); } But better, use a using block around your connection creation so it is automatically closed and disposed when it goes out of scope. Initializes a new instance of the NullReferenceException class, setting the Message property of the new instance to a system-supplied message that describes the error, such as "The value 'null' was found where an instance of an object was required." An API is a contract between a caller and a callee. For an attacker it provides an opportunity to stress the system in unexpected ways. . This message takes into account the current system culture. How can we prove that the supernatural or paranormal doesn't exist? (partial fix)) 1.0.5 (February 7, 2018) handle source files with any character encoding (issue 267) Scala 2.11.6 and 2.11.7 are now supported (issue 217) Fortify prioritizes and categorizes the findings so that we can address them immediately." I believe this particular behavior is a gap in the Fortify analyzer implementation, as all other static analysis tools seem to understand the code flow and will not complain about potential null references in this case. current ranch time (not your local time) is, dynamic table creation problem calling onchange, Need to Hide Table inside div:Code is Working Fine in FireFox but Not in IE..Please Help. Fortify flags this for null dereference. In C++, pointers are not guaranteed to be either NULL of have a valid value. Symantec security products include an extensive database of attack signatures. For example, if a program fails to call chdir() after calling chroot() , it violates the contract that specifies how to change the active root directory in a secure fashion. : System.getProperty may return NULL NPE.java(98) : allocated -> allocated : os may be null NPE.java(101) : allocated -> used : os.equalsIgnoreCase() : os used without null check[A423998C51F661CE8B2EB269BB0AF58D : low : Poor Logging Practice : Use of a System Output Stream : structural ] NPE.java(43)[5494E2A573D3F6F3F5F24DE49D893068 : low : J2EE Bad Practices : Leftover Debug Code : structural ] NPE.java(56)$ cat -n NPE.java 1 package npe; 2 3 import org.apache.commons.lang3.StringUtils; 4 5 public class NPE { 6 int v; 7 8 9 public NPE(int v) { 10 this.v = v; 11 } 12 13 14 public static int dangerousLength(String s) { 15 return s.length(); 16 } 17 18 19 public String stringify() { 20 if (v != 0) { 21 return "non-0"; 22 } else { 23 return null; 24 } 25 } 26 27 28 public NPE frugalCopy() { 29 if (v != 0) { 30 return new NPE(v); 31 } else { 32 return null; 33 } 34 } 35 36 37 public int getV() { 38 return v; 39 } 40 41 42 public static void log(String s) { 43 System.out.println(s); 44 } 45 46 47 public static String defaultIfEmpty(String s, String v) { 48 if (s == null || s.length() == 0) { 49 return v; 50 } else { 51 return s; 52 } 53 } 54 55 56 public static void main(String[] args) { 57 String arg = null; 58 if (args.length > 0) { 59 arg = args[0]; 60 } 61 log("arg is " arg); 62 63 // Fortify fails to catch a possible NPE when the null is passed as an 64 // argument.