HIGH CISA KEV

CVE-2024-36971

CVSS v3

7.8

HIGH

EPSS Score

0.6%

exploit probability

CISA KEV

Yes

known exploited

Exploitation

SSVC status

Description

In the Linux kernel, the following vulnerability has been resolved: net: fix __dst_negative_advice() race __dst_negative_advice() does not enforce proper RCU rules when sk->dst_cache must be cleared, leading to possible UAF. RCU rules are that we must first clear sk->sk_dst_cache, then call dst_release(old_dst). Note that sk_dst_reset(sk) is implementing this protocol correctly, while __dst_negative_advice() uses the wrong order. Given that ip6_negative_advice() has special logic against RTF_CACHE, this means each of the three ->negative_advice() existing methods must perform the sk_dst_reset() themselves. Note the check against NULL dst is centralized in __dst_negative_advice(), there is no need to duplicate it in various callbacks. Many thanks to Clement Lecigne for tracking this issue. This old bug became visible after the blamed commit, using UDP sockets.

CISA Known Exploited Vulnerability

Date Added
8/7/2024
Patch Due Date
8/28/2024
Ransomware Use
Unknown

Technical details

Published
6/10/2024

Frequently asked questions

What is CVE-2024-36971?

In the Linux kernel, the following vulnerability has been resolved: net: fix __dst_negative_advice() race __dst_negative_advice() does not enforce proper RCU rules when sk->dst_cache must be cleared, leading to possible UAF. RCU rules are that we must first clear sk->sk_dst_cache, then call dst_release(old_dst). Note that sk_dst_reset(sk) is implementing this protocol correctly, while __dst_negative_advice() uses the wrong order. Given that ip6_negative_advice() has special logic against RTF_CACHE, this means each of the three ->negative_advice() existing methods must perform the sk_dst_reset() themselves. Note the check against NULL dst is centralized in __dst_negative_advice(), there is no need to duplicate it in various callbacks. Many thanks to Clement Lecigne for tracking this issue. This old bug became visible after the blamed commit, using UDP sockets.

Is CVE-2024-36971 actively exploited?

Yes. CVE-2024-36971 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 8/28/2024.

What is the CVSS score for CVE-2024-36971?

CVE-2024-36971 has a CVSS v3 base score of 7.8 (HIGH severity).

Is CVE-2024-36971 affecting your environment?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.