CVE-2006-2083 in rsync
Summary
by MITRE
Integer overflow in the receive_xattr function in the extended attributes patch (xattr.c) for rsync before 2.6.8 might allow attackers to execute arbitrary code via crafted extended attributes that trigger a buffer overflow.
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Analysis
by VulDB Data Team • 06/18/2019
The vulnerability described in CVE-2006-2083 represents a critical integer overflow condition within the rsync file synchronization utility that affects versions prior to 2.6.8. This flaw exists in the extended attributes handling component of rsync, specifically within the receive_xattr function located in the xattr.c file. The vulnerability arises from insufficient input validation and improper integer handling when processing extended attributes during file synchronization operations, creating a potential pathway for remote code execution.
The technical implementation of this vulnerability stems from how rsync processes extended attributes when receiving files from remote systems. When the receive_xattr function processes crafted extended attributes, it fails to properly validate the size parameters of these attributes before allocating memory buffers. This integer overflow condition occurs when the size calculations exceed the maximum value that can be represented by the integer data type, causing the subsequent buffer allocation to be insufficient for the actual data being processed. The overflow results in memory corruption that can be exploited to overwrite adjacent memory locations, potentially allowing attackers to inject and execute arbitrary code with the privileges of the rsync process.
The operational impact of this vulnerability extends beyond simple data corruption, as it provides attackers with a potential vector for remote code execution within the context of the rsync service. Since rsync is commonly used for file synchronization across networks and often runs with elevated privileges, an attacker who successfully exploits this vulnerability could gain unauthorized access to systems running vulnerable versions of rsync. The attack typically requires the attacker to have the ability to control or influence the extended attributes of files being synchronized, which may be possible in scenarios where rsync is used to synchronize files from untrusted sources or when extended attributes are preserved during synchronization operations.
This vulnerability aligns with CWE-190, which describes integer overflow conditions, and represents a classic example of how improper integer handling can lead to memory corruption vulnerabilities. The ATT&CK framework categorizes this type of vulnerability under the 'Exploitation for Code Execution' tactic, where adversaries leverage software flaws to execute malicious code. The vulnerability also relates to CWE-121, which covers stack-based buffer overflow conditions, and CWE-122, which addresses heap-based buffer overflow scenarios, depending on how the memory corruption manifests during exploitation. Organizations using rsync in production environments should prioritize patching this vulnerability, as it represents a significant security risk that could be exploited by attackers with network access to systems running vulnerable versions of the software.
The remediation strategy for this vulnerability involves upgrading to rsync version 2.6.8 or later, which contains the necessary patches to address the integer overflow condition in the extended attributes processing. System administrators should also implement network segmentation and access controls to limit exposure to potentially malicious extended attributes, particularly when synchronizing files from untrusted sources. Additionally, monitoring for unusual extended attribute patterns and implementing proper input validation for file synchronization operations can help detect and prevent exploitation attempts. Regular security assessments of file synchronization processes and comprehensive vulnerability management programs should include verification of rsync versions to ensure all systems remain protected against known vulnerabilities.