CVE-2016-2315 in Git
Summary
by MITRE
revision.c in git before 2.7.4 uses an incorrect integer data type, which allows remote attackers to execute arbitrary code via a (1) long filename or (2) many nested trees, leading to a heap-based buffer overflow.
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Analysis
by VulDB Data Team • 07/10/2022
The vulnerability identified as CVE-2016-2315 represents a critical heap-based buffer overflow in the git version control system affecting releases prior to 2.7.4. This flaw stems from an incorrect integer data type usage within the revision.c file, specifically manifesting when processing certain file operations that involve long filenames or deeply nested directory structures. The vulnerability operates at the core of git's internal file handling mechanisms where improper type casting allows maliciously crafted inputs to overflow allocated memory buffers.
The technical exploitation of this vulnerability occurs through two primary attack vectors that leverage the same underlying flaw. The first vector involves feeding git with extremely long filenames that exceed the bounds of allocated memory buffers due to the incorrect integer type handling. The second vector exploits deeply nested directory trees where the recursive processing of nested structures causes integer overflows in memory allocation calculations. Both scenarios result in heap corruption that can be leveraged by remote attackers to execute arbitrary code on systems running vulnerable git versions. The integer data type issue typically involves signed vs unsigned integer mismatches that cause wraparound conditions during buffer size calculations.
From an operational impact perspective, this vulnerability presents significant risks to organizations relying on git for version control and source code management. Remote attackers can potentially compromise systems where git is installed and used, particularly in environments where git repositories are accessed over networks or when automated processes interact with git repositories. The vulnerability affects both local and remote repository operations, making it particularly dangerous in distributed development environments where multiple parties interact with the same repositories. The heap overflow nature of the vulnerability means that successful exploitation could lead to complete system compromise, data corruption, or denial of service conditions.
Security practitioners should prioritize immediate patching of all git installations running versions prior to 2.7.4 to prevent exploitation. The fix implemented in git 2.7.4 addresses the root cause by correcting the integer data type usage in revision.c, ensuring proper handling of buffer sizes during file name and directory tree processing. Organizations should also implement monitoring for unusual git operations that might indicate exploitation attempts, particularly around long filename operations or recursive directory processing. This vulnerability aligns with CWE-121, heap-based buffer overflow, and maps to attack techniques in the ATT&CK framework under execution and privilege escalation categories, emphasizing the need for comprehensive security controls around version control systems.
The vulnerability demonstrates the critical importance of proper integer type handling in security-critical code segments, particularly in systems that process untrusted input data. The flaw serves as a reminder that seemingly minor type casting issues can result in severe security consequences when combined with network-accessible functionality. Organizations should conduct thorough vulnerability assessments of their git installations and implement automated patch management processes to ensure timely remediation of similar issues. The security community has widely recognized this vulnerability as a prime example of how fundamental programming errors can create exploitable conditions in widely-used software components.