CVE-2006-0477 in Git
Summary
by MITRE
Buffer overflow in git-checkout-index in GIT before 1.1.5 allows remote attackers to execute arbitrary code via an index file with a long symbolic link.
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Analysis
by VulDB Data Team • 07/18/2018
The vulnerability described in CVE-2006-0477 represents a critical buffer overflow flaw within the git-checkout-index utility of the Git version control system prior to version 1.1.5. This issue arises from inadequate input validation when processing symbolic links within index files, creating a pathway for remote code execution attacks. The flaw specifically targets the handling of symbolic links that exceed predetermined buffer limits, allowing attackers to craft malicious index files that can trigger memory corruption during the checkout process.
The technical implementation of this vulnerability stems from a classic buffer overflow condition in the git-checkout-index component where symbolic link names are processed without proper boundary checks. When Git encounters an index file containing a symbolic link with an excessively long name, the system fails to validate the length of the link target before copying it into a fixed-size buffer. This buffer overflow occurs in the context of the index file processing routine, where the software assumes that symbolic link names will not exceed a certain length. The vulnerability is particularly dangerous because it can be exploited through remote repositories, meaning attackers do not need local access to the system to trigger the malicious behavior.
From an operational perspective, this vulnerability poses significant risks to organizations relying on Git for version control and code management. Attackers can exploit this weakness by pushing malicious index files to remote repositories, which, when checked out by unsuspecting users, will trigger the buffer overflow and potentially execute arbitrary code with the privileges of the user running git-checkout-index. The attack vector is particularly insidious because it can be delivered through standard Git operations such as git checkout or git pull, making it difficult to detect and prevent. This vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of how improper input validation can lead to remote code execution.
The impact of this vulnerability extends beyond individual system compromise to potentially affect entire development environments and CI/CD pipelines that rely on Git for code management. Organizations using older versions of Git are particularly at risk as the buffer overflow can be leveraged to gain unauthorized access to source code repositories, potentially leading to data exfiltration or further system compromise. The vulnerability also demonstrates the importance of input validation in version control systems, as the flaw exists in the fundamental processing of index files that are central to Git's operation. Mitigation strategies should include immediate upgrade to Git version 1.1.5 or later, implementation of proper input validation for symbolic links, and network segmentation to limit exposure to potentially malicious repositories. This vulnerability serves as a reminder of the critical importance of keeping version control systems updated and the potential security implications of buffer overflow conditions in widely used software tools. The flaw also intersects with ATT&CK technique T1578.001 which covers 'Modify Software: Create or Modify System Process' and T1059.007 which covers 'Command and Scripting Interpreter: PowerShell', highlighting how such vulnerabilities can be leveraged for privilege escalation and system compromise.