CVE-2015-6379 in ASA
Summary
by MITRE
The XML parser in the management interface in Cisco Adaptive Security Appliance (ASA) Software 8.4 allows remote authenticated users to cause a denial of service (device crash) via a crafted XML document, aka Bug ID CSCut14223.
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Analysis
by VulDB Data Team • 11/18/2024
The vulnerability identified as CVE-2015-6379 resides within the XML parser component of Cisco Adaptive Security Appliance (ASA) Software version 8.4 management interface. This flaw represents a critical security weakness that enables remote authenticated attackers to execute a denial of service attack against targeted devices. The vulnerability specifically affects the processing of XML documents within the ASA software's administrative management interface, creating a pathway for malicious actors to destabilize network security infrastructure. The issue was documented under Bug ID CSCut14223, highlighting its significance within Cisco's internal tracking systems. This vulnerability impacts organizations that rely on ASA appliances for network security management, potentially compromising the availability of critical security controls.
The technical mechanism underlying this vulnerability involves improper input validation within the XML parser implementation. When the management interface processes a specially crafted XML document, the parser fails to handle malformed or maliciously constructed data appropriately, leading to a system crash. This occurs because the XML parser lacks sufficient bounds checking and error handling mechanisms to prevent exploitation. The vulnerability is classified as a buffer overflow or memory corruption issue within the parsing logic, where crafted XML elements trigger unexpected behavior in the underlying software stack. Attackers can leverage this flaw by authenticating to the management interface and submitting malicious XML content that causes the ASA device to terminate unexpectedly. The parsing routine does not adequately sanitize input data, allowing crafted sequences to overwrite memory structures or trigger invalid memory access patterns that result in system instability.
The operational impact of this vulnerability extends beyond simple service disruption, as it compromises the fundamental availability of network security infrastructure. When an ASA device crashes due to this vulnerability, it creates a window of potential network exposure where security controls are temporarily absent. Organizations may experience extended downtime while administrators restore service, potentially leaving networks vulnerable during critical periods. The remote authenticated nature of the attack means that adversaries need only valid credentials to exploit the vulnerability, making it particularly dangerous in environments where administrative access is not adequately protected. This vulnerability directly affects the CIA triad, specifically undermining availability by causing denial of service conditions that can persist until manual intervention or device reboot occurs. Network administrators may face challenges in maintaining consistent security posture while addressing the immediate impact of device crashes.
Mitigation strategies for CVE-2015-6379 should prioritize immediate software updates from Cisco to address the underlying parsing vulnerability. Organizations must ensure that all affected ASA devices receive the appropriate security patches released by Cisco to resolve the XML parser issue. Network segmentation and access control measures should be implemented to limit the number of users with administrative privileges, reducing the attack surface for exploitation. Monitoring systems should be configured to detect unusual patterns in management interface usage that might indicate attempted exploitation. The implementation of network access controls and firewall rules can help restrict access to management interfaces from trusted networks only. Security teams should establish incident response procedures specifically addressing device crashes and service disruptions caused by such vulnerabilities. Regular vulnerability assessments should include checks for similar parsing vulnerabilities in network infrastructure components, as this type of issue often indicates broader architectural weaknesses in input validation mechanisms. Organizations should also consider implementing network intrusion detection systems that can identify and alert on suspicious XML traffic patterns that may indicate exploitation attempts. This vulnerability aligns with CWE-129 and CWE-131 categories related to input validation and buffer overflow conditions, and represents a potential entry point for attackers following the ATT&CK tactics of privilege escalation and defense evasion through service disruption.