CVE-2002-1165 in Sendmail
Summary
by MITRE
Sendmail Consortium s Restricted Shell (SMRSH) in Sendmail 8.12.6, 8.11.6-15, and possibly other versions after 8.11 from 5/19/1998, allows attackers to bypass the intended restrictions of smrsh by inserting additional commands after (1) "||" sequences or (2) "/" characters, which are not properly filtered or verified.
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Analysis
by VulDB Data Team • 09/07/2025
The vulnerability identified as CVE-2002-1165 resides within the Sendmail Consortium Restricted Shell implementation known as SMRSH, which was integrated into Sendmail versions 8.12.6, 8.11.6-15, and potentially other versions released after May 19, 1998. This flaw represents a critical security weakness that undermines the fundamental purpose of the restricted shell mechanism designed to prevent unauthorized command execution. The vulnerability operates through improper input validation and filtering mechanisms that fail to adequately sanitize command sequences, creating opportunities for privilege escalation and arbitrary code execution within the constrained environment.
The technical exploitation of this vulnerability occurs through specific manipulation of command sequences that bypass the intended restrictions of SMRSH. Attackers can insert additional commands immediately following either "||" logical OR operators or "/" character sequences, which the system fails to properly filter or validate. This improper handling creates a pathway for command injection attacks where malicious payloads can execute beyond the restricted shell boundaries. The vulnerability specifically targets the input parsing logic that should have prevented command chaining or path manipulation, demonstrating a failure in the security model implementation that allows attackers to escalate privileges and execute unauthorized system commands.
The operational impact of this vulnerability extends beyond simple command injection, representing a significant threat to system integrity and security posture. When exploited, the vulnerability enables attackers to bypass security controls that were specifically implemented to contain user commands within restricted environments, potentially leading to complete system compromise. This weakness affects systems where Sendmail serves as a mail transfer agent with restricted shell functionality, particularly impacting Unix-like systems where proper command isolation is critical. The vulnerability's exploitation can result in unauthorized access to sensitive system resources, data exfiltration, and establishment of persistent access mechanisms.
Security mitigations for this vulnerability require immediate patching of affected Sendmail installations to versions that properly address the input validation flaws in SMRSH. Organizations should implement comprehensive monitoring for suspicious command execution patterns and establish strict input validation policies for all shell command processing. The vulnerability aligns with CWE-78, which addresses improper neutralization of special elements used in OS commands, and reflects techniques described in the ATT&CK framework under privilege escalation and command and control categories. System administrators should also consider implementing additional security controls such as mandatory access controls, privilege separation mechanisms, and regular security audits to prevent exploitation of similar input validation weaknesses in other system components.