CVE-2002-1503 in Automatic File Distributor
Summary
by MITRE
Buffer overflow in Automatic File Distributor (AFD) 1.2.14 and earlier allows local users to gain privileges via a long MON_WORK_DIR environment variable or -w (workdir) argument to (1) afd, (2) afdcmd, (3) afd_ctrl, (4) init_afd, (5) mafd, (6) mon_ctrl, (7) show_olog, or (8) udc.
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Analysis
by VulDB Data Team • 02/26/2025
The vulnerability described in CVE-2002-1503 represents a critical buffer overflow flaw within the Automatic File Distributor (AFD) software suite version 1.2.14 and earlier. This issue affects multiple executables within the AFD ecosystem including core components such as afd, afdcmd, afd_ctrl, init_afd, mafd, mon_ctrl, show_olog, and udc. The vulnerability stems from insufficient input validation when processing environment variables and command line arguments, specifically targeting the MON_WORK_DIR environment variable and the -w (workdir) argument. The flaw exists because these components fail to properly bounds-check input data before copying it into fixed-size buffers, creating an exploitable condition that can be leveraged by local attackers to execute arbitrary code with elevated privileges.
The technical implementation of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient boundary checking allows attackers to overwrite adjacent memory locations. The AFD components process the MON_WORK_DIR environment variable and -w argument without adequate length validation, causing data to overflow into adjacent memory regions. This overflow can overwrite return addresses, function pointers, or other critical control data structures within the program's memory space. When these corrupted control structures are subsequently executed, they can redirect program flow to malicious code injected by the attacker, enabling privilege escalation from regular user level to system level access.
The operational impact of this vulnerability is particularly severe for systems running AFD software, as it provides local attackers with a straightforward path to privilege escalation without requiring network access or complex exploitation techniques. The vulnerability affects all executables within the AFD suite, meaning that exploitation can occur through any of the listed binaries, increasing the attack surface and potential vectors for compromise. Local privilege escalation vulnerabilities of this nature are particularly dangerous because they can be exploited by users who already have access to the system, potentially allowing them to bypass traditional security controls and gain unauthorized administrative access to critical file distribution services. The attack requires only local system access and the ability to set environment variables or pass command line arguments, making it accessible to any user with basic system privileges.
Mitigation strategies for this vulnerability should focus on immediate patching of the AFD software to version 1.2.15 or later, which contains the necessary buffer overflow protections and input validation fixes. System administrators should also implement proper access controls and privilege separation to limit local user access to these vulnerable executables. Additionally, environment variable sanitization and command line argument validation should be implemented at the system level to prevent malicious inputs from reaching vulnerable applications. Organizations should consider implementing runtime protections such as stack canaries or address space layout randomization to make exploitation more difficult. The vulnerability demonstrates the importance of proper input validation and bounds checking in system software, aligning with ATT&CK technique T1068 which covers privilege escalation through local exploits. Regular security assessments and vulnerability scanning should be conducted to identify similar buffer overflow conditions in other legacy software components that may be similarly vulnerable to exploitation.