CVE-2005-0686 in mlterm
Summary
by MITRE
Integer overflow in mlterm 2.5.0 through 2.9.1, with gdk-pixbuf support enabled, allows remote attackers to execute arbitrary code via a large image file that is used as a background.
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Analysis
by VulDB Data Team • 07/01/2021
The vulnerability described in CVE-2005-0686 represents a critical integer overflow condition within the mlterm terminal emulator version 2.5.0 through 2.9.1 when gdk-pixbuf support is enabled. This flaw exists in the handling of image files used as backgrounds, creating a pathway for remote attackers to execute arbitrary code on affected systems. The vulnerability specifically targets the memory allocation mechanisms within the image processing pipeline where the software fails to properly validate image dimensions before attempting to allocate memory for image rendering.
The technical implementation of this vulnerability stems from improper bounds checking during image file processing. When mlterm encounters a large image file designated as a background, the software attempts to calculate memory requirements based on image dimensions without adequate validation of integer values. This allows attackers to craft malicious image files with deliberately oversized dimensions that cause integer overflow during memory allocation calculations. The resulting overflow produces a smaller memory allocation than intended, leading to memory corruption that can be exploited to overwrite critical memory regions and ultimately execute arbitrary code with the privileges of the affected process.
From an operational perspective, this vulnerability poses significant risk to systems that utilize mlterm with gdk-pixbuf support, particularly in environments where users might encounter untrusted image files. The remote exploitation capability means attackers can deliver malicious background images through various vectors including web browsers, email attachments, or file sharing systems. The vulnerability affects not only individual user systems but also server environments where terminal emulators might be used for remote access or automated processes. The integer overflow condition creates a classic buffer overflow scenario that can be leveraged for privilege escalation and system compromise, making it particularly dangerous in multi-user or networked environments.
Security practitioners should recognize this vulnerability as mapping to CWE-190, Integer Overflow or Wraparound, which is categorized under the broader class of weaknesses related to integer handling errors. The attack pattern aligns with ATT&CK technique T1059.007 for execution through terminal commands and potentially T1068 for privilege escalation if successful exploitation occurs. Mitigation strategies should include immediate patching of affected mlterm versions, disabling gdk-pixbuf support where possible, implementing strict file validation for image backgrounds, and monitoring for suspicious image file usage patterns. System administrators should also consider implementing network-level controls to restrict access to potentially malicious image files and establish proper input validation for all image processing components within terminal emulators. The vulnerability demonstrates the importance of robust integer overflow protection in multimedia processing components and highlights the need for comprehensive security testing of image handling code in terminal applications.