An unauthenticated remote attacker can trigger a kernel memory leak in the Linux net/sched/act_ct subsystem, leading to system exhaustion and denial of service.

The vulnerability exists in the tcf_ct_handle_fragments function, which fails to properly free sk_buff structures when header sanity checks reject a packet. This results in an unauthenticated attacker being able to leak kernel memory by sending specifically crafted, malformed packets to the affected system.

The vulnerability carries a CVSS score of 7.5, reflecting its high impact on system availability. Successful exploitation allows an attacker to exhaust system memory by repeatedly sending malformed packets, causing a denial of service on critical network infrastructure. This could lead to significant operational downtime for services relying on the affected Linux kernel.

Immediate Action: Apply the latest stable kernel updates (5.15.217, 6.1.184, or 6.6.152) provided by your Linux distribution maintainer as soon as possible.

Proactive Monitoring: Monitor system memory usage and kernel logs for unusual patterns or OOM (Out of Memory) events that may indicate active exploitation attempts.

Compensating Controls: While no direct WAF patch exists for this kernel-level issue, employing network traffic filtering to drop malformed or anomalous packets at the network perimeter can reduce the exposure to this attack vector.

Public Exploit Available: Unknown

Given the potential for remote denial of service, administrators should prioritize patching the Linux kernel across all affected production systems. Verify that your distribution has released the specific stable updates mentioned, as these contain the necessary fixes to prevent sk_buff memory leakage. Testing these updates in a staging environment before widespread deployment is recommended to ensure compatibility.