CVE-2007-5935 in teTeX
Summary
by MITRE
Stack-based buffer overflow in hpc.c in dvips in teTeX and TeXlive 2007 and earlier allows user-assisted attackers to execute arbitrary code via a DVI file with a long href tag.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 07/31/2019
The vulnerability identified as CVE-2007-5935 represents a critical stack-based buffer overflow flaw within the dvips component of teTeX and TeXlive 2007 distributions. This issue specifically affects the hpc.c source file which processes DVI files during the conversion process from DVI format to PostScript. The vulnerability arises from inadequate input validation when processing the href tag attribute within DVI files, creating a condition where maliciously crafted input can overwrite adjacent memory locations on the stack.
The technical exploitation of this vulnerability occurs through user-assisted attack vectors where an attacker must convince a victim to process a specially crafted DVI file containing an excessively long href tag. When the dvips utility processes such a file, the malformed href tag triggers a buffer overflow that can be leveraged to execute arbitrary code with the privileges of the user running the dvips utility. This represents a classic stack-based buffer overflow scenario where the overflow corrupts the return address and potentially other critical stack variables, allowing attackers to redirect program execution flow.
From an operational perspective, this vulnerability poses significant risks to systems processing DVI documents, particularly in environments where users may encounter untrusted documents from external sources. The impact extends beyond simple code execution to potential privilege escalation scenarios, as the compromised dvips utility may run with elevated privileges depending on system configuration. This vulnerability affects a wide range of Unix-like systems that utilize the teTeX or TeXlive distributions for document processing, making it a widespread concern for organizations maintaining document processing infrastructure.
The vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which specifically addresses buffer overflows occurring in stack memory regions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. This flaw also maps to ATT&CK technique T1059.007 Command and Scripting Interpreter: PowerShell, as the arbitrary code execution capability could enable attackers to leverage PowerShell or similar scripting environments for further exploitation. The vulnerability demonstrates how seemingly benign document processing utilities can become attack vectors when insufficient input validation is implemented, highlighting the importance of secure coding practices in utility applications that process external data.
Mitigation strategies for this vulnerability include immediate patching of affected teTeX and TeXlive installations to versions containing fixed implementations of the dvips utility. System administrators should implement strict input validation policies for DVI file processing and consider sandboxing or containerization of document processing utilities to limit potential damage from successful exploitation attempts. Additionally, users should be educated about the risks of processing untrusted DVI files and organizations should establish robust update management procedures to ensure timely deployment of security patches. The vulnerability underscores the necessity of regular security assessments of document processing pipelines and the importance of implementing defense-in-depth strategies that include network segmentation and access controls for systems handling document conversion tasks.