A vulnerability in the extract_status_code() function of Keepalived could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on a targeted system.
The vulnerability is due to improper parsing of HTTP responses when the extract_status_code() function, as defined in the lib/html.c source code file of the affected software, does not validate HTTP status codes and writes a significant amount of content to heap memory. An attacker could exploit this vulnerability by sending a request that submits malicious input to a targeted system. A successful exploit could result in a heap-based overflow condition that the attacker could use to cause a DoS condition.
Proof-of-concept (PoC) code that demonstrates an exploit of this vulnerability is publicly available.
Keepalived.org has confirmed the vulnerability and released software updates.
To exploit this vulnerability, the attacker may send a request that submits malicious input to the targeted system, making exploitation more difficult in environments that restrict network access from untrusted sources.
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Administrators are advised to run both firewall and antivirus applications to minimize the potential of inbound and outbound threats.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators can help protect affected systems from external attacks by using a solid firewall strategy.
Administrators are advised to monitor affected systems.
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Cisco Multivendor Vulnerability Alerts respond to vulnerabilities identified in third-party vendors' products. These alerts contain information compiled from diverse sources and provide comprehensive technical descriptions, objective analytical assessments, workarounds and practical safeguards, and links to vendor advisories and patches.