CVE-2025-30472: Analyzing the Corosync Stack-based Buffer Overflow Vulnerability and its Exploitation

The Corosync Cluster Engine is an essential open-source project that is widely implemented for creating highly available and fault-tolerant systems. However, a concerning vulnerability, identified as CVE-2025-30472, has recently emerged within this crucial software. This vulnerability could potentially allow an attacker to cause a stack-based buffer overflow, leading to remote code execution, denial of service, or potentially compromising the entire system.

This post will delve into the details and exploitation of this bug, discussing the cause and consequences, while also providing code snippets and reference links to help understand the issue more comprehensively.

What is the Vulnerability?

CVE-2025-30472 affects Corosync versions up to and including 3.1.9. If encryption is either disabled or the attacker knows the encryption key, a stack-based buffer overflow can occur. This flaw is located in the orf_token_endian_convert function in the exec/totemsrp.c file. It can be triggered through a large UDP packet.

Reference: Corosync Security Advisory CVE-2025-30472

Cause of the Vulnerability

The vulnerability is caused by the lack of validation for input sizes in the orf_token_endian_convert function. When the function handles a large UDP packet, it does not check if the input size exceeds the buffer's assigned size, which results in a buffer overflow.

Here's a code snippet from exec/totemsrp.c

static void orf_token_endian_convert (const void *in, void *out)
{
	const unsigned int *in_uint32_t = (const unsigned int *)in;
	unsigned int *out_uint32_t = (unsigned int *)out;
	out_uint32_t[] = swab32 (in_uint32_t[]);
	out_uint32_t[1] = swab32 (in_uint32_t[1]);
        ...
}

Exploiting the Vulnerability

To exploit this vulnerability, an attacker may craft a malicious UDP packet that features an input size greater than the buffer size. When the packet reaches the unpatched version of Corosync, the uncontrolled buffer overflow may lead to various potential attack scenarios, including remote code execution, denial of service, and system compromise.

Original References

1. https://nvd.nist.gov/vuln/detail/CVE-2025-30472
2. https://github.com/corosync/corosync/security/advisories/GHSA-vvj2-5wpj-v964
3. https://access.redhat.com/security/cve/CVE-2025-30472

Mitigation

To mitigate this security risk, users are strongly recommended to update Corosync to the latest version (3.1.10 or later). This will help establish a secure environment and protection against possible exploitation.

In addition, employ encryption and avoid sharing encryption keys with unauthorized parties. This will eliminate the threat from attackers who would need to know the encryption key to exploit this vulnerability.

Conclusion

This post demonstrates the significance and potential risks associated with CVE-2025-30472, a stack-based buffer overflow vulnerability affecting Corosync. By understanding this flaw, highlighting the relevant code snippets, and identifying ways to mitigate and prevent exploitation, we can tackle such threats effectively and proactively safeguard our systems and applications.

Timeline

Published on: 03/22/2025 02:15:16 UTC
Last modified on: 04/01/2025 20:28:02 UTC