Linux Kernel up to 4.18 TCP tcp_retransmit_timer resource consumption

Summaryinfo

A vulnerability was found in Linux Kernel up to 4.18 and classified as problematic. Affected by this issue is the function tcp_retransmit_timer of the component TCP Handler. Executing a manipulation can lead to resource consumption. This vulnerability is tracked as CVE-2024-41007. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 4.18. It has been declared as problematic. This vulnerability affects the function tcp_retransmit_timer of the component TCP Handler. The manipulation with an unknown input leads to a resource consumption vulnerability. The CWE definition for the vulnerability is CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. As an impact it is known to affect availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: tcp: avoid too many retransmit packets If a TCP socket is using TCP_USER_TIMEOUT, and the other peer retracted its window to zero, tcp_retransmit_timer() can retransmit a packet every two jiffies (2 ms for HZ=1000), for about 4 minutes after TCP_USER_TIMEOUT has 'expired'. The fix is to make sure tcp_rtx_probe0_timed_out() takes icsk->icsk_user_timeout into account. Before blamed commit, the socket would not timeout after icsk->icsk_user_timeout, but would use standard exponential backoff for the retransmits. Also worth noting that before commit e89688e3e978 ("net: tcp: fix unexcepted socket die when snd_wnd is 0"), the issue would last 2 minutes instead of 4.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2024-41007 since 07/12/2024. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 207802 (Ubuntu 20.04 LTS : Linux kernel vulnerabilities (USN-7003-4)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.19 eliminates this vulnerability. Applying the patch 97a9063518f1 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (207802). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14
• 4.15
• 4.16
• 4.17
• 4.18

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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Once again VulDB remains the best source for vulnerability data.

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