CVE-2008-7160 in Silc Toolkit
Summary
by MITRE
The silc_http_server_parse function in lib/silchttp/silchttpserver.c in the internal HTTP server in silcd in Secure Internet Live Conferencing (SILC) Toolkit before 1.1.9 allows remote attackers to overwrite a stack location and possibly execute arbitrary code via a crafted Content-Length header, related to incorrect use of a %lu format string.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 03/22/2025
The vulnerability described in CVE-2008-7160 affects the Secure Internet Live Conferencing (SILC) Toolkit version 1.1.8 and earlier, specifically within the internal HTTP server component known as silcd. This flaw resides in the silc_http_server_parse function located in lib/silchttp/silchttpserver.c, which processes HTTP requests and responses within the SILC framework. The vulnerability represents a critical security weakness that could potentially allow remote attackers to execute arbitrary code on affected systems, making it a significant concern for organizations relying on SILC for secure communications.
The technical root cause of this vulnerability stems from improper handling of the Content-Length HTTP header within the silc_http_server_parse function. When processing HTTP requests, the function incorrectly utilizes a %lu format string for parsing the Content-Length header value, which creates a potential buffer overflow condition. This improper format string usage allows attackers to manipulate the parsing logic by crafting malicious Content-Length header values that can overwrite adjacent stack memory locations. The vulnerability specifically manifests when the HTTP server processes requests containing specially crafted Content-Length headers that exceed expected boundaries, enabling attackers to overwrite stack variables and potentially redirect program execution flow.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it can enable remote code execution on systems running vulnerable versions of the SILC Toolkit. Attackers exploiting this flaw could gain unauthorized access to systems, potentially leading to complete compromise of the affected infrastructure. The vulnerability affects the internal HTTP server functionality that is part of the broader SILC communication framework, which is designed for secure internet conferencing and messaging services. Organizations using SILC for sensitive communications face heightened risk since the vulnerability could be exploited to intercept, modify, or disrupt secure communications channels. The attack vector requires only network access to send crafted HTTP requests to the vulnerable server, making it particularly dangerous in environments where the internal HTTP server is exposed to external networks.
Security practitioners should note that this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of improper format string usage leading to memory corruption. The flaw also maps to ATT&CK technique T1059, which involves executing malicious code through command injection or code execution vulnerabilities. Organizations should prioritize immediate remediation by upgrading to SILC Toolkit version 1.1.9 or later, which contains the necessary patches to address this memory corruption issue. Additional mitigations include implementing network segmentation to limit access to the affected internal HTTP server, monitoring for suspicious Content-Length header values in HTTP traffic, and deploying intrusion detection systems capable of identifying crafted HTTP requests targeting this specific vulnerability. The vulnerability underscores the importance of proper input validation and format string handling in security-critical applications, particularly in components that process external network requests and data.