CVE-2008-1246 in Pix Asa Finesse Operation System
Summary
by MITRE
** DISPUTED ** The Cisco PIX/ASA Finesse Operation System 7.1 and 7.2 allows local users to gain privileges by entering characters at the enable prompt, erasing these characters via the Backspace key, and then holding down the Backspace key for one second after erasing the final character. NOTE: third parties, including one who works for the vendor, have been unable to reproduce the flaw unless the enable password is blank.
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Analysis
by VulDB Data Team • 01/17/2025
The vulnerability described in CVE-2008-1246 represents a privilege escalation flaw within Cisco PIX/ASA Finesse Operating System versions 7.1 and 7.2. This issue resides in the command-line interface handling mechanism where the system fails to properly validate input sequences during enable mode authentication. The vulnerability operates through a specific interaction pattern that exploits a race condition or input buffer handling flaw in the terminal processing subsystem. Security researchers have identified this as potentially allowing local attackers with console access to escalate their privileges from user level to administrative level without proper authentication. The flaw manifests specifically when users interact with the enable prompt through a particular sequence of keystrokes involving backspace operations. This vulnerability type aligns with CWE-254, which encompasses security weaknesses related to improper handling of input validation and privilege management in operating systems.
The technical implementation of this vulnerability involves the interaction between keyboard input processing and terminal prompt handling within the Cisco ASA operating system. When a user attempts to enter an enable password and subsequently uses backspace to correct their input, the system's input buffer management appears to fail during the specific sequence where the backspace key is held down for one second after erasing the final character. This particular timing and sequence of operations may cause the system to misinterpret the input buffer state, potentially allowing unauthorized privilege escalation. The vulnerability demonstrates a classic example of improper input validation and state management within privileged execution contexts. According to ATT&CK framework category T1068, this represents an exploitation of local privilege escalation techniques that leverage operating system weaknesses to gain elevated privileges. The underlying flaw suggests inadequate sanitization of terminal input sequences and potentially improper handling of input stream states during authentication processes.
The operational impact of this vulnerability extends beyond simple privilege escalation as it represents a fundamental weakness in the authentication mechanism of network security appliances. Local attackers who can access the console interface of affected Cisco ASA devices could potentially bypass authentication controls entirely, gaining full administrative access to the device. This would allow them to modify firewall rules, access sensitive network traffic, alter security policies, and potentially use the compromised device as a pivot point for attacks on other network segments. The vulnerability affects critical network infrastructure components that serve as security gateways, making the potential impact severe for organizations relying on these appliances for network protection. The specific conditions required to exploit this vulnerability, including the need for physical console access and the precise keystroke sequence, limit its exposure but do not eliminate the risk entirely. Organizations with access control policies that allow unauthorized console access or those with legacy systems running these vulnerable versions face significant operational risks.
The mitigation strategies for this vulnerability involve both immediate remediation and long-term architectural improvements. Cisco has released patches and updates to address this specific flaw in later versions of the ASA operating system. Organizations should immediately upgrade to patched versions of the software, ensuring that all affected devices receive the necessary security updates. Additionally, implementing strict physical access controls to network equipment, including securing console ports and limiting administrative access, provides crucial defense-in-depth measures. Network segmentation and monitoring of administrative activities can help detect unauthorized privilege escalation attempts. The vulnerability also highlights the importance of proper input validation and terminal handling in security-critical systems, suggesting that similar issues may exist in other network operating systems. Organizations should conduct thorough vulnerability assessments of their network infrastructure and implement comprehensive security monitoring to detect potential exploitation attempts. The incident underscores the necessity of regular security updates and the importance of validating security patches before deployment in production environments.