CVE-2001-0855 in ClearCase
Summary
by MITRE
Buffer overflow in db_loader in ClearCase 4.2 and earlier allows local users to gain root privileges via a long TERM environment variable.
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Analysis
by VulDB Data Team • 10/02/2025
The vulnerability identified as CVE-2001-0855 represents a critical buffer overflow flaw within the db_loader component of IBM Rational ClearCase version 4.2 and earlier systems. This issue resides in the handling of environment variables, specifically the TERM environment variable, which is commonly used by terminal emulators to determine terminal capabilities and characteristics. The vulnerability occurs when the db_loader process processes a maliciously crafted TERM variable that exceeds the allocated buffer space, leading to memory corruption that can be exploited by local attackers.
The technical implementation of this vulnerability stems from inadequate input validation within the db_loader utility, which is responsible for loading database information in ClearCase environments. When a local user sets an overly long TERM environment variable, the application fails to properly bounds-check the input before copying it into a fixed-size buffer. This classic buffer overflow condition allows an attacker to overwrite adjacent memory locations, potentially including return addresses or other critical control data structures. The flaw is particularly dangerous because it operates within a privileged context, as db_loader typically runs with elevated privileges necessary for database operations.
The operational impact of this vulnerability extends beyond simple local privilege escalation, as it provides attackers with a pathway to gain root access on systems running vulnerable ClearCase installations. This compromise can lead to complete system takeover, data exfiltration, and persistent access within the network environment. The vulnerability affects organizations using older ClearCase versions where patching may be delayed or restricted due to compatibility concerns with existing development workflows. Security analysts should note that this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a common attack vector that has been documented in numerous security assessments.
Mitigation strategies for this vulnerability should prioritize immediate patching of affected ClearCase installations to version 4.3 or later where the buffer overflow has been addressed. Organizations should implement strict environment variable validation policies and consider deploying runtime protections such as stack canaries or address space layout randomization to reduce exploitability. System administrators should also conduct thorough inventory assessments to identify all systems running vulnerable ClearCase versions and establish monitoring procedures to detect unusual environment variable usage patterns. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically T1068, which involves exploiting vulnerabilities to gain elevated privileges. Additionally, organizations should consider implementing principle of least privilege controls to minimize the potential impact of such vulnerabilities, ensuring that even if exploitation occurs, the attacker's access remains limited to prevent broader system compromise.