CVE-2007-1357 in Linux
Summary
by MITRE
The atalk_sum_skb function in AppleTalk for Linux kernel 2.6.x before 2.6.21, and possibly 2.4.x, allows remote attackers to cause a denial of service (crash) via an AppleTalk frame that is shorter than the specified length, which triggers a BUG_ON call when an attempt is made to perform a checksum.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 12/20/2024
The vulnerability described in CVE-2007-1357 represents a critical flaw in the AppleTalk protocol implementation within the Linux kernel version 2.6.x prior to 2.6.21 and potentially affecting the 2.4.x series. This issue resides within the atalk_sum_skb function which handles AppleTalk frame processing, specifically when dealing with malformed network packets that do not conform to expected length specifications. The flaw demonstrates a classic buffer overflow condition where the kernel fails to properly validate packet boundaries before attempting cryptographic checksum operations.
The technical exploitation of this vulnerability occurs when a remote attacker crafts an AppleTalk frame that is deliberately shorter than the minimum expected length required for proper processing. When the kernel's atalk_sum_skb function encounters such a malformed packet, it triggers an unconditional BUG_ON call which results in an immediate kernel panic and system crash. This behavior directly violates the fundamental principle of robust error handling in kernel space code and represents a failure in input validation mechanisms. The vulnerability operates at the network protocol layer and can be exploited remotely without requiring any authentication or privileged access.
The operational impact of this vulnerability extends beyond simple denial of service to potentially compromising system availability and stability within networks relying on AppleTalk protocols. When exploited successfully, the vulnerability causes complete system crashes that can disrupt network services and require manual intervention for system recovery. The affected systems may include servers, workstations, and embedded devices that utilize Linux kernels with AppleTalk support, particularly in legacy network environments where AppleTalk remains in use. This vulnerability represents a significant risk to network infrastructure where continuous availability is critical.
Mitigation strategies for CVE-2007-1357 should prioritize immediate kernel updates to versions 2.6.21 or later where the vulnerability has been patched. System administrators should also implement network segmentation to isolate affected systems and consider disabling AppleTalk protocol support entirely if the service is not required. Network monitoring solutions should be configured to detect and alert on anomalous AppleTalk traffic patterns that may indicate exploitation attempts. The vulnerability aligns with CWE-129, which addresses improper validation of input boundaries, and maps to ATT&CK technique T1499.004 for network denial of service attacks. Additionally, implementing proper input validation and defensive programming practices in kernel modules can prevent similar vulnerabilities from manifesting in other protocol implementations. Organizations should conduct thorough vulnerability assessments to identify all systems running affected kernel versions and ensure complete patch management across their infrastructure to prevent exploitation.