CVE-2000-1004 in OpenBSD
Summary
by MITRE
Format string vulnerability in OpenBSD photurisd allows local users to execute arbitrary commands via a configuration file directory name that contains formatting characters.
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Analysis
by VulDB Data Team • 05/28/2018
The vulnerability identified as CVE-2000-1004 represents a critical format string flaw within the photurisd daemon of OpenBSD systems. This daemon serves as a key component in the IPsec security framework, responsible for managing security associations and key exchange protocols. The vulnerability specifically manifests when the daemon processes configuration file directory names that contain formatting characters such as %s, %d, or other format specifiers typically used in printf-style functions. This flaw falls under the category of CWE-134, which describes the use of a non-constant string as the format string in functions like printf, sprintf, or vprintf, creating a direct path for malicious input manipulation.
The technical exploitation of this vulnerability occurs when a local attacker manipulates the configuration file directory name to include format specifiers that cause the photurisd daemon to interpret memory contents as command instructions. When the daemon processes such malformed directory names, it fails to properly sanitize the input before passing it to format string functions, allowing attackers to inject malicious payloads that can execute arbitrary code with the privileges of the photurisd process. This creates a significant privilege escalation vector since the daemon typically runs with elevated system permissions necessary for IPsec operations. The vulnerability is particularly dangerous because it requires only local access to exploit, making it accessible to any user who can modify configuration files or influence the daemon's input processing.
The operational impact of CVE-2000-1004 extends beyond simple command execution, as it can enable attackers to completely compromise the IPsec security infrastructure on affected OpenBSD systems. Since photurisd is integral to establishing secure network connections and managing cryptographic keys, successful exploitation could lead to complete network infiltration, data exfiltration, and disruption of security services. The vulnerability also aligns with ATT&CK technique T1068, which describes 'Exploitation for Privilege Escalation' by leveraging local vulnerabilities to gain elevated system privileges. Additionally, the flaw demonstrates characteristics of T1211, 'Exploitation for Defense Evasion', as attackers could potentially use the compromised daemon to hide their activities or establish persistent access points within the network infrastructure. The impact is further amplified by the fact that IPsec is often used in enterprise environments for secure communications, making successful exploitation particularly damaging to network security posture.
Mitigation strategies for this vulnerability should focus on immediate patching of the OpenBSD system with the appropriate security updates that address the format string handling in photurisd. System administrators should also implement strict input validation for all configuration files processed by security daemons, ensuring that directory names and other user-supplied inputs are properly sanitized before processing. Network segmentation and privilege separation techniques can help limit the potential impact of successful exploitation, while monitoring systems should be configured to detect unusual behavior in IPsec-related processes. The vulnerability serves as a prime example of why input validation and proper secure coding practices are essential in security-critical applications, particularly those handling cryptographic protocols where the consequences of exploitation can be severe. Organizations should also consider implementing automated patch management systems to ensure timely remediation of such vulnerabilities, as the timeframe between vulnerability disclosure and exploitation often determines the severity of impact in real-world scenarios.