CVE-2003-0396 in linux-atm
Summary
by MITRE
Buffer overflow in les for ATM on Linux (linux-atm) before 2.4.1, if used setuid, allows local users to gain privileges via a long -f command line argument.
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Analysis
by VulDB Data Team • 11/10/2024
The vulnerability described in CVE-2003-0396 represents a critical buffer overflow flaw within the les utility component of the linux-atm package version 2.4.1 and earlier. This issue specifically affects systems where the les program is installed with setuid permissions, creating a privilege escalation vector that can be exploited by local attackers. The les utility is part of the ATM (Asynchronous Transfer Mode) networking framework for linux systems, designed to handle ATM network connections and configurations.
The technical implementation of this vulnerability stems from inadequate input validation within the les program's command line argument processing. When the -f flag is used with a sufficiently long argument string, the program fails to properly bounds-check the input data before copying it into a fixed-size buffer. This classic buffer overflow condition occurs because the program does not validate the length of the -f argument against the allocated buffer space, allowing an attacker to overwrite adjacent memory locations including return addresses and other critical program state information.
The operational impact of this vulnerability is severe as it enables local users to escalate their privileges from standard user level to root access. Since the les program operates with elevated privileges due to its setuid bit being set, an attacker can exploit this flaw to execute arbitrary code with root permissions. The attack vector requires local system access but does not need network connectivity, making it particularly dangerous in multi-user environments where privilege separation is crucial for system security. This vulnerability directly maps to CWE-121, which describes stack-based buffer overflow conditions, and can be categorized under ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation'.
The mitigation strategy for this vulnerability involves immediate patching of the linux-atm package to version 2.4.1 or later where the buffer overflow has been corrected. System administrators should also conduct thorough audits to identify all instances of setuid programs that may be susceptible to similar issues and implement proper input validation mechanisms. Additionally, the principle of least privilege should be enforced by removing unnecessary setuid permissions from programs that do not require elevated privileges for their normal operation. Regular security assessments and vulnerability scanning should be implemented to identify and remediate similar buffer overflow conditions in other system components, ensuring compliance with security standards such as those outlined in the Common Weakness Enumeration catalog and MITRE ATT&CK framework.