CVE-2024-41007 tcp: avoid too many retransmit packets
A remote attacker can cause excessive TCP retransmissions and resource consumption by manipulating window sizes, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-41007?
CVE-2024-41007 is a high-severity denial of service vulnerability in Linux kernel, published on 15 Jul 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2024-41007?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-41007?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-41007 being exploited?
There is no known exploitation of CVE-2024-41007 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-43392, AZL-43399, BELL-CVE-2024-41007, DEBIAN-CVE-2024-41007, GHSA-2jcw-rxcr-pwmp, UBUNTU-CVE-2024-41007.