CVE-2010-0827 in TeX Live
Summary
by MITRE
Integer overflow in dvips in TeX Live 2009 and earlier, and teTeX, allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted virtual font (VF) file associated with a DVI file.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 09/09/2021
The vulnerability identified as CVE-2010-0827 represents a critical integer overflow flaw within the dvips component of TeX Live 2009 and earlier versions, as well as in teTeX distributions. This issue stems from improper handling of integer values during the processing of virtual font files that are embedded within DVI documents. The flaw occurs when the dvips utility processes specially crafted VF files that contain malformed integer values, leading to unexpected behavior in memory allocation and buffer management. The vulnerability is particularly concerning because it can be exploited through remote attack vectors, allowing malicious actors to trigger the overflow condition simply by providing a crafted VF file that gets processed as part of a DVI document. This type of vulnerability falls under CWE-190, which specifically addresses integer overflow conditions that can lead to memory corruption and arbitrary code execution. The ATT&CK framework categorizes this as a vulnerability exploitation technique under the broader category of code injection, where an attacker leverages memory corruption to achieve unauthorized code execution.
The technical implementation of this vulnerability involves the dvips utility's parsing logic for virtual font files, where integer values representing font metrics, character dimensions, or other font-related parameters are not properly validated before being used in memory allocation operations. When these integers exceed their maximum representable values, the overflow causes subsequent calculations to produce incorrect results, leading to buffer overflows or other memory corruption scenarios. The flaw specifically manifests when processing font data structures where the expected integer values are manipulated to exceed the bounds of their data type, causing the application to allocate insufficient memory or access invalid memory regions. This type of integer overflow is particularly dangerous in the context of document processing utilities because these applications often handle untrusted input from external sources, making them prime targets for exploitation.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to potentially enable remote code execution on systems running affected versions of TeX Live or teTeX. When exploited successfully, the integer overflow can cause the dvips application to crash or behave unpredictably, but in some cases, attackers may be able to manipulate the overflow to inject and execute arbitrary code within the context of the application process. This makes the vulnerability particularly dangerous for systems that process untrusted documents or serve as part of document processing workflows in enterprise environments. The vulnerability affects a wide range of systems that rely on TeX-based document processing, including academic institutions, publishing platforms, and document management systems that utilize these tools for typesetting and document generation. The attack surface is broad because DVI files are commonly used in academic and technical document processing, making it likely that vulnerable systems would encounter such files in normal operations.
Mitigation strategies for CVE-2010-0827 primarily involve upgrading to patched versions of TeX Live or teTeX distributions that contain fixes for the integer overflow conditions in dvips. System administrators should ensure that all affected systems are updated to versions that properly validate integer values during VF file processing and implement proper bounds checking mechanisms. Additionally, implementing strict input validation and sanitization for DVI and VF files can help reduce the risk of exploitation, particularly in environments where processing untrusted documents is unavoidable. Organizations should also consider implementing network segmentation and access controls to limit exposure to potentially malicious VF files, while monitoring for suspicious file processing activities that might indicate exploitation attempts. The fix typically involves adding proper integer overflow checks and ensuring that all font-related parameters are validated against expected ranges before being used in memory allocation operations, thereby preventing the conditions that lead to the vulnerable integer overflow scenarios.