CVE-2008-1994 in acon
Summary
by MITRE
Multiple stack-based buffer overflows in (a) acon.c, (b) menu.c, and (c) child.c in Acon 1.0.5-5 through 1.0.5-7 allow local users to execute arbitrary code via (1) a long HOME environment variable or (2) a large number of terminal columns.
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Analysis
by VulDB Data Team • 09/23/2018
The vulnerability described in CVE-2008-1994 represents a critical security flaw affecting Acon version 1.0.5-5 through 1.0.5-7, where multiple stack-based buffer overflows exist across three distinct source files. These buffer overflows occur in acon.c, menu.c, and child.c, creating exploitable conditions that can be leveraged by local attackers to execute arbitrary code on affected systems. The vulnerability stems from inadequate input validation and memory management practices within these specific code modules, allowing attackers to manipulate memory layout through carefully crafted inputs that exceed allocated buffer boundaries.
The technical exploitation of this vulnerability occurs through two primary vectors that target different system environment parameters. The first attack vector involves manipulating the HOME environment variable to create a buffer overflow condition when the application processes excessively long pathnames. The second vector exploits terminal column count parameters, where an attacker can specify a large number of terminal columns to trigger the same memory corruption issues. Both attack scenarios demonstrate the classic stack-based buffer overflow pattern where attacker-controlled data overflows into adjacent memory regions, potentially overwriting return addresses and function pointers. This vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a fundamental flaw in memory management practices within the application's input handling mechanisms.
The operational impact of this vulnerability extends beyond simple code execution, as local users with minimal privileges can leverage these flaws to gain elevated system access. The exploitation process typically involves crafting malicious inputs that cause the application to write beyond allocated memory boundaries, potentially leading to arbitrary code execution with the privileges of the affected user. This creates a significant security risk for systems where Acon is installed, particularly in multi-user environments where local privilege escalation can provide attackers with persistent access to system resources. The vulnerability affects the application's core functionality and can potentially lead to complete system compromise if exploited successfully. Attackers can use these buffer overflows to manipulate program execution flow, inject malicious payloads, or establish backdoors within the system.
Mitigation strategies for this vulnerability should focus on immediate code patching and input validation improvements. System administrators should prioritize updating to patched versions of Acon where these buffer overflows have been addressed through proper memory boundary checks and input sanitization. The recommended approach involves implementing proper bounds checking mechanisms in the affected source files, specifically ensuring that environment variable processing and terminal parameter handling include adequate buffer size validation. Additionally, implementing stack canary protections and address space layout randomization can provide additional defense-in-depth measures. Organizations should also consider implementing monitoring for suspicious environment variable usage and terminal configuration changes that might indicate exploitation attempts. The vulnerability's classification under the ATT&CK framework would align with techniques involving privilege escalation and code injection, making it a critical target for security hardening and vulnerability management programs.