CVE-2008-1227 in Silc Toolkit
Summary
by MITRE
Stack-based buffer overflow in the silc_fingerprint function in lib/silcutil/silcutil.c in Secure Internet Live Conferencing (SILC) Toolkit 1.1.5, and unspecified earlier versions, allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via long input data. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 08/07/2019
The vulnerability identified as CVE-2008-1227 represents a critical stack-based buffer overflow in the Secure Internet Live Conferencing (SILC) Toolkit, specifically within the silc_fingerprint function located in lib/silcutil/silcutil.c. This flaw affects version 1.1.5 and potentially earlier releases of the SILC toolkit, creating a significant security risk that can be exploited remotely by attackers. The vulnerability stems from inadequate input validation and bounds checking within the cryptographic fingerprint processing routine, which is a fundamental component of the SILC protocol's security infrastructure. The affected function fails to properly validate the length of input data before copying it to a fixed-size stack buffer, creating an exploitable condition that can be leveraged for malicious purposes.
The technical implementation of this vulnerability occurs when the silc_fingerprint function processes user-supplied data without sufficient boundary checks, allowing an attacker to supply input data that exceeds the allocated buffer space on the stack. This overflow condition can overwrite adjacent stack memory locations, including return addresses and function parameters, potentially leading to unpredictable program behavior. The attack vector is particularly concerning as it operates over network connections, making it accessible to remote adversaries who can craft malicious input to trigger the buffer overflow. According to CWE classification, this represents a classic stack-based buffer overflow vulnerability (CWE-121) that falls under the broader category of buffer overflow conditions (CWE-119) and can be categorized under the ATT&CK technique of Code Injection (T1059) when exploited for arbitrary code execution. The vulnerability's impact is severe as it can result in either a denial of service condition where the application crashes and becomes unavailable, or more critically, allow for arbitrary code execution on the target system.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire security infrastructure of systems utilizing the affected SILC toolkit. When exploited for code execution, an attacker could gain unauthorized access to systems, escalate privileges, or establish persistent backdoors within the network. The nature of the SILC protocol, which is designed for secure internet conferencing and communication, means that successful exploitation could lead to unauthorized access to sensitive communications, data interception, or complete system compromise. The vulnerability's remote exploitability means that attackers do not require physical access or local system privileges to carry out attacks, significantly expanding the attack surface and potential impact. Organizations using SILC toolkit implementations may experience service outages, data breaches, or unauthorized access to their secure communication channels, making this vulnerability particularly dangerous in environments where secure communications are paramount. The lack of proper input sanitization in cryptographic functions like fingerprint processing creates a dangerous precedent where security-critical components become attack vectors for privilege escalation and system compromise.
Mitigation strategies for CVE-2008-1227 should include immediate patching of affected systems with the vendor-supplied security updates, as well as implementing network-level restrictions and monitoring for suspicious input patterns. System administrators should consider applying input validation measures at network boundaries to detect and block malformed data before it reaches vulnerable applications. The implementation of stack protection mechanisms such as stack canaries and address space layout randomization (ASLR) can provide additional defense-in-depth layers against exploitation attempts. Organizations should also conduct thorough vulnerability assessments to identify all systems running affected versions of the SILC toolkit and ensure proper network segmentation to limit the potential impact of successful exploitation attempts. Regular security audits and penetration testing should be performed to identify similar vulnerabilities in other cryptographic libraries and security protocols. The vulnerability serves as a reminder of the critical importance of proper input validation in security-sensitive code and demonstrates how seemingly minor implementation flaws in cryptographic functions can lead to severe security consequences. Given the age of this vulnerability and its classification as a stack-based buffer overflow, organizations should also consider migrating away from deprecated protocols and libraries that may contain similar unpatched vulnerabilities.