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Programmers should be wary when freeing memory in a loop or conditional statement; if coded incorrectly, these constructs can lead to double-free vulnerabilities. It is also a common error to misuse the realloc()
function in a manner that results in double-free vulnerabilities. (See MEM04-C. Beware of zero-length allocations.)
Rule | Severity | Likelihood | Remediation Cost | Priority | Level |
---|---|---|---|---|---|
MEM30-C | High | Likely | Medium | P18 | L1 |
Automated Detection
Tool | Version | Checker | Description | ||||
---|---|---|---|---|---|---|---|
Astrée |
|
Supported, but no explicit checker | |||||||||
CodeSonar |
| ALLOC.UAF | Use after free | ||||||
Compass/ROSE |
| USE_AFTER_FREE | Can detect the specific instances where memory is deallocated more than once or read/written to the target of a freed pointer | |||||||
Klocwork |
| UFM.DEREF.MIGHT |
LDRA tool suite |
| 51 D, 484 S, 112 D | Partially implemented | ||||||
Parasoft C/C++test |
|
|
| BD-RES-FREE |
Parasoft Insure++ |
Detects accessing freed memory at runtime | |||||||
Polyspace Bug Finder | R2016a | Deallocation of previously deallocated pointer, Use of previously freed pointer | Memory freed more than once without allocation Memory accessed after deallocation | ||||
Splint |
|
PRQA QA-C | 9.1 | 1769, 1770 |
PRQA QA-C++ | 4.2 | 3339, 4303, 4304 |
PVS-Studio | 6.22 | V586, V774 | General analysis rule set |
Related Vulnerabilities
VU#623332 describes a double-free vulnerability in the MIT Kerberos 5 function krb5_recvauth().
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Key here (explains table format and definitions)
Taxonomy | Taxonomy item | Relationship |
---|---|---|
CERT C Secure Coding Standard | MEM01-C. Store a new value in pointers immediately after free() | Prior to 2018-01-12: CERT: Unspecified Relationship |
CERT C | MEM50-CPP. Do not access freed memory | Prior to 2018-01-12: CERT: Unspecified Relationship |
ISO/IEC TR 24772:2013 | Dangling References to Stack Frames [DCM] | Prior to 2018-01-12: CERT: Unspecified Relationship |
ISO/IEC TR 24772:2013 | Dangling Reference to Heap [XYK] | Prior to 2018-01-12: CERT: Unspecified Relationship |
ISO/IEC TS 17961 | Accessing freed memory [accfree] | Prior to 2018-01-12: CERT: Unspecified Relationship |
ISO/IEC TS 17961 | Freeing memory multiple times [dblfree] | Prior to 2018-01-12: CERT: Unspecified Relationship |
MISRA C:2012 | Rule 18.6 (required) | Prior to 2018-01-12: CERT: Unspecified Relationship |
CWE 2.11 | CWE-416, Use After Free | 2017-07-07: CERT: Exact |
CWE 2.11 | CWE-672 | 2017-07-07: CERT: Rule subset of CWE |
CERT-CWE Mapping Notes
Key here for mapping notes
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- Dereference of a pointer after freeing it (besides passing it to free() a second time)
Bibliography
[ISO/IEC 9899:2011] | 7.22.3, "Memory Management Functions" |
[Kernighan 1988] | Section 7.8.5, "Storage Management" |
[OWASP Freed Memory] |
[MIT 2005] |
[Seacord 2013b] | Chapter 4, "Dynamic Memory Management" |
[Viega 2005] | Section 5.2.19, "Using Freed Memory" |
[VU#623332] |
[xorl 2009] | CVE-2009-1364: LibWMF Pointer Use after free() |
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