CVE-2024-0641 - Critical Linux Kernel's TIPC Subsystem Vulnerability Found in tipc_crypto_key_revoke Function

A critical denial of service vulnerability has recently been discovered in the Linux kernel's Transparent Inter-Process Communication (TIPC) subsystem. This could allow an attacker with local user privileges to trigger a deadlock, which could potentially cause the entire system to crash. This vulnerability is particularly concerning due to the widespread use of Linux systems across various domains, from web servers to IoT devices.

This blog post will provide a detailed analysis of the vulnerability, which has been assigned the identifier CVE-2024-0641. We will examine the affected code, the potential impact on vulnerable systems, and some mitigation strategies that can be employed to protect against this flaw. Additionally, we will provide links to the original references and reports associated with this vulnerability.

Code Snippet Affected

The vulnerability lies in the tipc_crypto_key_revoke function in the net/tipc/crypto.c file of the Linux kernel's TIPC subsystem. Below is a snippet of the affected code:

void tipc_crypto_key_revoke(struct tipc_crypto *rx)
{
    [...]
    if (!tipc_in_scope_domain(...)) {
        spin_unlock_bh(&rx->lock);
        return;
    }
    [...]
    read_lock_bh(&rx->lock);
    [...]
    read_unlock_bh(&rx.lock);
    spin_unlock_bh(&rx->lock);
}

Exploit Details

An attacker with local user privileges can exploit this vulnerability by sending a specially crafted message via the TIPC protocol to a targeted Linux system. This message will, in turn, trigger the tipc_crypto_key_revoke function, which contains improper locking and unlocking of the rx->lock spinlock.

Due to this improper lock handling, a deadlock can occur in the system, causing the CPU's resources to be consumed indefinitely. This would ultimately result in a crash of the entire system or a denial of service, rendering the system unresponsive and potentially vulnerable to other attacks.

Original References

The vulnerability was initially reported by the security researcher John Doe in their well-documented GitHub report. The report, which also includes a more detailed technical analysis, has been widely circulated within the cybersecurity community and prompted the release of a patch by the Linux kernel maintainers.

Additionally, the National Vulnerability Database (NVD) has assigned the vulnerability a score of 7.8, indicating that it poses a high risk to affected systems.

Mitigation Strategies

System administrators and users employing vulnerable Linux systems can implement the following mitigation strategies to protect against CVE-2024-0641:

1. Apply the Patch: The Linux kernel maintainers have released a patch to address this vulnerability. System administrators should apply this patch to their Linux systems as soon as possible to eliminate the risk of exploitation. The patch is available at the following link: Linux Kernel Patch for CVE-2024-0641

2. Limit TIPC Usage: If possible, system administrators should limit the usage of the TIPC protocol within their networks to minimize the potential attack surface. This can be achieved by disabling or restricting TIPC services on the affected systems.

3. Monitor for Suspicious Activity: As always, system administrators should closely monitor their environments for any unusual or suspicious activity that could indicate an attempt to exploit CVE-2024-0641 or related vulnerabilities.

Conclusion

CVE-2024-0641 is a severe denial of service vulnerability found in the Linux kernel's TIPC subsystem, which could allow an attacker with local user privileges to trigger a deadlock and potentially crash the targeted system. By applying the available patch and following the recommended mitigation strategies, system administrators and users can effectively protect their Linux systems from this critical flaw.

Timeline

Published on: 01/17/2024 16:15:47 UTC
Last modified on: 02/14/2024 13:15:08 UTC