CVE-2012-1423 in Rising
Summary
by MITRE
The TAR file parser in Command Antivirus 5.2.11.5, Emsisoft Anti-Malware 5.1.0.1, F-Prot Antivirus 4.6.2.117, Fortinet Antivirus 4.2.254.0, Ikarus Virus Utilities T3 Command Line Scanner 1.1.97.0, K7 AntiVirus 9.77.3565, NOD32 Antivirus 5795, Norman Antivirus 6.06.12, PC Tools AntiVirus 7.0.3.5, Rising Antivirus 22.83.00.03, and VirusBuster 13.6.151.0 allows remote attackers to bypass malware detection via a POSIX TAR file with an initial MZ character sequence. NOTE: this may later be SPLIT into multiple CVEs if additional information is published showing that the error occurred independently in different TAR parser implementations.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 02/16/2019
The vulnerability described in CVE-2012-1423 represents a critical flaw in multiple antivirus products' handling of TAR file archives, specifically targeting their file format parsing mechanisms. This issue affects a wide range of security solutions including Command Antivirus, Emsisoft, F-Prot, Fortinet, and numerous other commercial and open-source antivirus platforms. The flaw manifests when these security applications encounter POSIX TAR files that contain an initial MZ character sequence, which is typically associated with Windows executable files rather than archive formats. This particular combination of file characteristics creates a parsing anomaly that allows malicious actors to exploit the vulnerability and bypass security detection measures.
The technical root cause of this vulnerability lies in the improper validation and interpretation of file headers within the TAR archive parsing logic. When these antivirus solutions encounter a TAR file beginning with the MZ signature, their parsers fail to correctly identify the file type and instead treat it as a potential executable, thereby skipping the proper archive extraction and scanning procedures. This behavior stems from a fundamental flaw in how these security applications prioritize file type detection, where the presence of the MZ signature overrides the expected TAR file structure validation. The vulnerability is classified under CWE-122, which deals with buffer overflow conditions, and specifically relates to improper input validation in file format parsers. The issue demonstrates a classic case of insufficient sanitization of file metadata, where the security software fails to properly validate the file's actual content against its claimed format.
The operational impact of this vulnerability extends far beyond simple detection bypass, as it represents a fundamental weakness in the defensive infrastructure of numerous organizations relying on these antivirus solutions. Attackers can leverage this flaw by crafting malicious TAR archives that contain embedded malware payloads, knowing that these files will be processed through the vulnerable parsers and potentially delivered to target systems without proper scanning. This creates a significant risk for enterprise environments where multiple antivirus products are deployed across various network segments, as the vulnerability affects a broad spectrum of security tools. The implications are particularly severe in environments where these antivirus solutions are deployed as network-based security controls or are used in automated scanning processes, as the vulnerability could allow for persistent malware delivery through seemingly benign archive files.
Mitigation strategies for CVE-2012-1423 require immediate action from security administrators to update affected antivirus solutions to versions that properly address the TAR file parsing issue. Organizations should prioritize patching all affected products, including Command Antivirus, Emsisoft, F-Prot, and others mentioned in the vulnerability description, as the issue affects multiple vendors and implementations. System administrators should also implement additional network-based controls such as file type filtering at network perimeters and enhanced monitoring for suspicious file patterns that might indicate exploitation attempts. The vulnerability's characteristics align with techniques described in the MITRE ATT&CK framework under the T1059.007 sub-technique for Windows command shell execution, as attackers may use the bypassed detection to establish persistent access through malicious archive files. Security teams should also consider implementing file integrity monitoring solutions that can detect and alert on suspicious file type combinations that might indicate exploitation attempts targeting this specific vulnerability.