CVE-2003-1439 in Silc Client
Summary
by MITRE
Secure Internet Live Conferencing (SILC) 0.9.11 and 0.9.12 stores passwords and sessions in plaintext in memory, which could allow local users to obtain sensitive information.
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Analysis
by VulDB Data Team • 07/05/2017
The Secure Internet Live Conferencing (SILC) protocol implementation in versions 0.9.11 and 0.9.12 contains a critical security flaw that exposes sensitive authentication data through improper memory handling practices. This vulnerability represents a classic case of insecure data storage in memory, where authentication credentials and session information are maintained in plaintext format rather than being properly encrypted or obfuscated. The flaw directly violates fundamental security principles regarding the protection of sensitive information, creating an attack surface that local adversaries can exploit to gain unauthorized access to confidential data.
The technical implementation of this vulnerability stems from the application's failure to implement proper memory sanitization and encryption mechanisms for authentication tokens and session data. When SILC processes user authentication requests and maintains active sessions, it stores these critical pieces of information in memory without adequate protection measures. This plaintext storage approach means that any local user with access to the system can potentially extract this sensitive data through various memory inspection techniques, including direct memory dumping, process analysis, or exploitation of memory corruption vulnerabilities that may exist in the application's memory management subsystem.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable privilege escalation and persistent access to secured communication channels. Local users who can execute code on the target system gain immediate access to active sessions and authentication credentials, which could allow them to impersonate legitimate users within the SILC network. This creates a significant risk for environments where SILC is used for secure communications, as attackers can leverage this information to maintain access to confidential conversations and potentially compromise the entire communication infrastructure. The vulnerability aligns with CWE-312 (CWE-312: Cleartext Storage of Sensitive Information) and represents a clear violation of the principle of least privilege.
From an adversary perspective, this vulnerability provides a straightforward path to information extraction without requiring complex exploitation techniques or network-level attacks. The attack surface is reduced to local system access, making it particularly dangerous in multi-user environments where privilege separation is not properly enforced. Attackers can utilize tools such as memory dumps, process inspection utilities, or even simple file system access to extract the plaintext credentials stored in memory. This vulnerability also intersects with ATT&CK technique T1003 (OS Credential Dumping) and T1059 (Command and Scripting Interpreter) as local users can leverage these capabilities to extract and utilize the stored credentials. The risk is amplified in environments where multiple users share the same system or where system administrators maintain elevated privileges that could be compromised through this memory-based attack vector.
Mitigation strategies for this vulnerability should focus on implementing proper memory encryption and sanitization mechanisms within the SILC implementation. The most effective approach involves modifying the application to encrypt sensitive data in memory using strong encryption algorithms and ensuring that memory is properly sanitized after credential usage. Additionally, system administrators should implement strict access controls and privilege separation to limit local user access to critical system resources. The implementation of memory protection mechanisms such as stack canaries, address space layout randomization, and heap metadata protection can further reduce the exploitability of this vulnerability. Regular security audits and code reviews should be conducted to identify similar patterns of insecure data handling in other components of the system.