CVE-2015-0860 in dpkg
Summary
by MITRE
Off-by-one error in the extracthalf function in dpkg-deb/extract.c in the dpkg-deb component in Debian dpkg 1.16.x before 1.16.17 and 1.17.x before 1.17.26 allows remote attackers to execute arbitrary code via the archive magic version number in an "old-style" Debian binary package, which triggers a stack-based buffer overflow.
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Analysis
by VulDB Data Team • 12/01/2024
The vulnerability identified as CVE-2015-0860 represents a critical stack-based buffer overflow flaw within the dpkg-deb component of Debian dpkg software suite. This issue specifically affects versions prior to 1.16.17 and 1.17.26, creating a dangerous condition where remote attackers can exploit the system through manipulated archive magic version numbers in old-style Debian binary packages. The vulnerability stems from an off-by-one error in the extracthalf function located within dpkg-deb/extract.c, which fundamentally undermines the software's ability to properly handle buffer boundaries during package extraction processes.
The technical implementation of this flaw occurs when the dpkg-deb utility processes Debian binary packages using the older format specification. The extracthalf function, responsible for extracting data from these packages, contains a boundary condition error that allows an attacker to manipulate the magic version number field within the package header. This manipulation causes the function to write data beyond the allocated buffer space, resulting in a stack-based buffer overflow. The flaw is particularly dangerous because it allows arbitrary code execution with the privileges of the user running the dpkg-deb utility, potentially leading to complete system compromise. The off-by-one error creates a scenario where one additional byte of data can be written beyond the intended buffer limits, enabling attackers to overwrite adjacent memory locations including return addresses and function pointers.
The operational impact of CVE-2015-0860 extends beyond simple privilege escalation to encompass full system compromise capabilities. When exploited, this vulnerability allows remote attackers to execute arbitrary code on systems running affected versions of dpkg, making it particularly dangerous in environments where package installation occurs automatically or through untrusted sources. The attack vector is particularly concerning because it can be triggered through standard package management operations, meaning that simply downloading or installing a malicious Debian package could result in system compromise. This vulnerability directly maps to CWE-121 Stack-based Buffer Overflow, which is classified under the Common Weakness Enumeration framework as a fundamental memory safety issue. The attack pattern aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter: PowerShell, though the actual exploitation occurs at the binary level rather than through scripting.
Mitigation strategies for this vulnerability require immediate patching of affected systems to upgrade to dpkg versions 1.16.17 or 1.17.26 and later, which contain the necessary fixes for the buffer overflow condition. Organizations should implement comprehensive package management policies that prevent installation of untrusted packages and establish regular update schedules to maintain system security. System administrators should also consider implementing network segmentation and access controls to limit exposure of systems running vulnerable versions of dpkg. Additional defensive measures include monitoring package installation activities and implementing automated patch management systems to ensure timely deployment of security updates. The vulnerability demonstrates the critical importance of proper input validation and buffer boundary checking in system utilities, particularly those involved in package management and system installation processes. Organizations should also conduct regular security assessments of their package management infrastructure to identify and remediate similar vulnerabilities that may exist in other system components.