Linux Kernel cipso_v4_validate Denial of Service Vulnerability [CVE-2013-7470]

CVE Number – CVE-2013-7470

A vulnerability in the Common IP Security Option (CIPSO) validation implementation in the Linux Kernel could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on a targeted system.

The vulnerability exists in the cipso_v4_validate() function, as defined in the include/net/cipso_ipv4.hsource code file, and is due to an improper memory loop that the affected function could enter if opt[opt_iter +1] == 0 when CONFIG_NETLABEL is disabled. This could cause the symmetric multiprocessing (SMP) CPU that is executing the function to become unresponsive to inter-processor interrupts (IPIs), resulting in a kernel crash. An attacker could exploit this vulnerability by sending packets that submit malicious input to the affected software. A successful exploit could allow the attacker to cause the system to become unresponsive, resulting in a DoS condition.Proof-of-concept (PoC) code that demonstrates an exploit of this vulnerability is publicly available.kernel.org has confirmed the vulnerability and released software updates.

Analysis

• To exploit this vulnerability, an attacker must send a request that submits malicious input to the targeted system, making exploitation more difficult in environments that restrict network access from untrusted sources.

Safeguards

• 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.

Vendor Announcements

• kernel.org has confirmed the vulnerability in a changelog at the following link: net: fix cipso packet validation when !NETLABEL

Fixed Software

• kernel.org has released updated software at the following link: The Linux Kernel Archives