CVE-2025-21707

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A vulnerability has been identified in the Linux kernel related to the MultiPath TCP (MPTCP) protocol. The issue arises from the way MPTCP maintains the status of received sub-options, which can lead to inconsistent status and potentially cause problems. The vulnerability was discovered by syzbot, which triggered a path where a relevant bitfield is not cleared or initialized, resulting in an uninit-value bug. This bug can occur in various functions, including mptcp expand seq, mptcp expand seq, ack update msk, and mptcp incoming options. The vulnerability can be exploited through the tcp data queue and tcp rcv established functions.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.