CVE-2023-38710

Description

An assertion failure flaw was found in the Libreswan package that occurs when processing IKEv2 REKEY requests. When an IKEv2 Child SA REKEY packet contains an invalid IPsec protocol ID number of 0 or 1, an error notification INVALID_SPI is sent back. The notify payload's protocol ID is copied from the incoming packet, but the code that verifies outgoing packets fails an assertion that the protocol ID must be ESP (2) or AH(3). This flaw allows a malicious client or attacker to send a malformed IKEv2 REKEY packet, causing a crash and restarting the libreswan pluto daemon. When sent continuously, this could lead to a denial of service attack.

Statement

IKEv2 REKEY requests are only processed when received from authenticated peers, limiting the scope of possible attackers to peers who have successfully authenticated.

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 HatNVDcve.org
Base Score6.56.5N/A
Attack VectorNetworkNetworkN/A
Attack ComplexityLowLowN/A
Privileges RequiredLowLowN/A
User InteractionNoneNoneN/A
ScopeUnchangedUnchangedN/A
ConfidentialityNoneNoneN/A
Integrity ImpactNoneNoneN/A
Availability ImpactHighHighN/A

Vector

Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

NVD: 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.

Acknowledgements

Red Hat would like to thank X1AOxiang for reporting this issue.

Frequently Asked Questions

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