CVE-2010-2055 in Gpl Ghostscript
Summary
by MITRE
Ghostscript 8.71 and earlier reads initialization files from the current working directory, which allows local users to execute arbitrary PostScript commands via a Trojan horse file, related to improper support for the -P- option to the gs program.
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Analysis
by VulDB Data Team • 09/20/2021
The vulnerability described in CVE-2010-2055 represents a critical security flaw in Ghostscript versions 8.71 and earlier that stems from improper handling of initialization files during program execution. This issue specifically affects the gs program's processing of the -P- option, which is designed to control the handling of PostScript files and initialization parameters. The fundamental problem occurs when Ghostscript attempts to load configuration files from the current working directory without proper validation of file sources or paths, creating an environment where malicious actors can exploit this behavior to execute arbitrary code.
The technical implementation of this vulnerability exploits the trust model inherent in Ghostscript's initialization file processing mechanism. When users execute the gs program with the -P- option, the software attempts to read configuration files from the current working directory to establish the initial environment settings. This design flaw allows attackers to place malicious PostScript files with specific names in directories where they have write access, effectively creating a Trojan horse scenario where legitimate program execution becomes a vector for code injection. The vulnerability is particularly dangerous because it operates at the file system level without requiring elevated privileges, making it accessible to local users who may not possess administrative rights.
From an operational impact perspective, this vulnerability enables local privilege escalation and arbitrary code execution within the context of the user running Ghostscript. Attackers can craft malicious PostScript files that contain harmful commands, which are then executed when the gs program processes these files during normal operation. The implications extend beyond simple code execution, as this vulnerability can be leveraged to bypass security controls, access sensitive data, or establish persistent access points on compromised systems. The attack vector is particularly insidious because it requires no network connectivity or external resources beyond the local file system, making detection and prevention more challenging.
The vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, and CWE-78, which covers improper neutralization of special elements used in OS commands. These classifications reflect the core issue of insufficient input validation and path traversal limitations that allow the program to process files from untrusted locations. From an ATT&CK framework perspective, this vulnerability maps to T1059.007 for command and scripting interpreter, specifically focusing on postscript execution, and T1068 for exploit for privilege escalation. The attack chain typically involves placing malicious files in strategic locations, executing the gs program with the -P- option, and leveraging the initialization file processing to execute unauthorized commands.
Mitigation strategies for CVE-2010-2055 require immediate patching of affected Ghostscript installations to versions 8.72 or later where this vulnerability has been addressed. System administrators should implement strict file system permissions and access controls to limit write access to directories where Ghostscript may be executed, particularly preventing users from creating files in locations where the program expects to load initialization data. Additional defensive measures include monitoring for unusual file creation patterns in directories where Ghostscript operates, implementing application whitelisting policies, and conducting regular security audits to identify potential privilege escalation vectors. Network segmentation and least privilege principles should be enforced to limit the potential impact of successful exploitation attempts, while regular system updates and vulnerability assessments help maintain overall security posture against similar threats.