CVE-2024-3652
Description
A flaw was found in Libreswan, where it was identified to contain an assertion failure issue in the compute_proto_keymat() function. The vulnerability can be exploited when an IKEv1 connection is loaded with an AH/ESP default setting when no esp= line is present in the connection. This flaw allows an authenticated attacker to send the bogus AES-GMAC proposal request, triggering the issue and causing Libreswan to crash and restart. When this connection is automatically added on startup using the auto= keyword, it can cause repeated crashes, leading to a denial of service. No remote code execution is possible.
Statement
The CVE-2024-3652 vulnerability in Libreswan is classified as a moderate severity issue due to its limited scope and impact. While the vulnerability can lead to Denial of Service (DoS) by causing the Libreswan service to crash and restart, it does not allow for Remote Code Execution or expose sensitive data. Additionally, the exploitation of this vulnerability requires specific conditions to be met: an IKEv1 connection loaded without an esp= line and the peer to have authenticated itself. Furthermore, IKEv2 connections are not vulnerable to this issue.
Mitigation
An esp= line using a common IKEv1 algorithm list can be added to all IKEv1 based connections. An example of such an esp= line could be:
esp=aes-sha2_512,aes-sha1,aes-sha2_256,aes-md5,3des-sha1,3des-md5
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker that can trigger an assert statement can still lead to a denial of service if the relevant code can be triggered by an attacker, and if the scope of the assert() extends beyond the attacker's own session.
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