CVE-2010-4165 in Linux
Summary
by MITRE
The do_tcp_setsockopt function in net/ipv4/tcp.c in the Linux kernel before 2.6.37-rc2 does not properly restrict TCP_MAXSEG (aka MSS) values, which allows local users to cause a denial of service (OOPS) via a setsockopt call that specifies a small value, leading to a divide-by-zero error or incorrect use of a signed integer.
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Analysis
by VulDB Data Team • 10/23/2024
The vulnerability identified as CVE-2010-4165 represents a critical flaw in the Linux kernel's TCP implementation that affects systems running versions prior to 2.6.37-rc2. This issue resides within the do_tcp_setsockopt function located in the net/ipv4/tcp.c source file, where inadequate validation of TCP_MAXSEG (Maximum Segment Size) parameters creates a pathway for malicious exploitation. The flaw specifically targets the handling of MSS values during socket configuration operations, demonstrating a fundamental failure in input validation that can be exploited by local attackers to disrupt system operations.
The technical root cause of this vulnerability stems from improper bounds checking on TCP_MAXSEG values when processing setsockopt system calls. When a local user executes a setsockopt call with an intentionally small MSS value, the kernel's TCP implementation fails to validate that the specified value remains within acceptable operational parameters. This validation gap leads to two primary failure modes: a divide-by-zero error that occurs when the kernel attempts mathematical operations using the invalid MSS value, and incorrect usage of signed integer arithmetic that can result in unexpected behavior during TCP connection handling. The vulnerability manifests as an OOPS (Oops) condition, which represents a kernel-level error that typically results in system instability or complete system crash.
The operational impact of this vulnerability extends beyond simple denial of service to potentially compromise system availability and stability. Local attackers can exploit this weakness to cause system-wide disruptions by triggering kernel panics or forcing the kernel to enter an unrecoverable state. The vulnerability is particularly dangerous because it requires only local user privileges to exploit, making it accessible through any user account on the system. Systems running affected kernel versions become susceptible to persistent denial of service attacks that can be initiated by any local user, potentially allowing for prolonged system unavailability or complete system shutdown. This characteristic places the vulnerability in the category of privilege escalation risks, as local users can leverage it to cause broader system instability.
Mitigation strategies for CVE-2010-4165 primarily focus on kernel version updates and immediate system patching to ensure compliance with the fixed implementation. Organizations should prioritize upgrading to Linux kernel versions 2.6.37-rc2 or later, where the validation logic has been corrected to properly restrict TCP_MAXSEG values. Additionally, system administrators should implement monitoring solutions to detect unusual socket configuration activities that might indicate exploitation attempts. The vulnerability aligns with CWE-129, which addresses improper validation of array indices, and demonstrates characteristics consistent with ATT&CK technique T1068, which involves exploiting local system privileges for privilege escalation. Network segmentation and access control measures can provide additional defense-in-depth layers, though the most effective protection remains timely kernel patching and system updates.