CVE-2005-2927 in UnixWare
Summary
by MITRE
Stack-based buffer overflow in ppp in SCO Unixware 7.1.3 and 7.1.4, and possibly earlier versions, allows local users to execute arbitrary code via a long argument to the (1) prompt or (2) defprompt command.
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Analysis
by VulDB Data Team • 06/06/2019
The vulnerability identified as CVE-2005-2927 represents a critical stack-based buffer overflow flaw within the ppp component of SCO Unixware operating systems. This issue affects versions 7.1.3 and 7.1.4, with potential implications for earlier releases in the product line. The vulnerability resides in the handling of command-line arguments for two specific commands: prompt and defprompt, which are integral to the Point-to-Point Protocol implementation used for establishing network connections. The flaw stems from insufficient input validation mechanisms that fail to properly constrain the length of user-provided arguments, creating an exploitable condition where maliciously crafted input can overwrite adjacent memory locations on the stack.
The technical implementation of this vulnerability involves the manipulation of command arguments passed to the ppp daemon or related utilities. When a local user executes either the prompt or defprompt command with an excessively long argument string, the system fails to validate the input length against predetermined buffer boundaries. This oversight allows the overflow to occur within the stack memory allocation, potentially overwriting return addresses, saved registers, and other critical stack data structures. The vulnerability is classified as local privilege escalation since it requires a user to already have access to the system, but the successful exploitation can lead to arbitrary code execution with elevated privileges. This type of vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and demonstrates how improper input validation can create dangerous memory corruption scenarios.
The operational impact of CVE-2005-2927 extends beyond simple privilege escalation as it provides attackers with a pathway to gain unauthorized control over system resources. Local users who exploit this vulnerability can execute malicious code with the privileges of the ppp service or the user who invoked the vulnerable commands, potentially leading to complete system compromise. The attack vector is relatively straightforward since it requires only local access and knowledge of the specific command structure, making it particularly dangerous in environments where local user access is not strictly controlled. This vulnerability represents a significant risk in multi-user systems where untrusted local users might have access to command-line interfaces, as it can be leveraged to establish persistent backdoors or to escalate privileges to root access levels. The implications are further exacerbated by the fact that this vulnerability affects enterprise-level operating systems used for mission-critical applications, where unauthorized access can result in substantial data breaches and service disruptions.
Mitigation strategies for CVE-2005-2927 should prioritize immediate patching of affected SCO Unixware systems, as the vendor would have released security updates addressing the buffer overflow condition. System administrators should implement strict input validation controls and consider disabling or restricting access to the vulnerable prompt and defprompt commands when not essential for network configuration. Additional protective measures include implementing proper privilege separation for ppp-related processes, monitoring for unusual command execution patterns, and conducting regular security audits of system configurations. The vulnerability's classification under ATT&CK technique T1068, which covers local privilege escalation, suggests that defensive measures should focus on limiting local user capabilities and implementing robust access controls. Organizations should also consider network segmentation to prevent lateral movement if exploitation occurs, and maintain comprehensive system monitoring to detect anomalous behavior associated with privilege escalation attempts. Regular security assessments and vulnerability scanning should include verification of patched status for all SCO Unixware components to ensure complete remediation of this and related buffer overflow vulnerabilities.