SB20250329117 - Anolis OS update for unbound
Published: March 29, 2025
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Resource management error (CVE-ID: CVE-2024-33655)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to way Unbound queues DNS requests, which makes it susceptible to DNSBomb attack. A remote attacker with ability to control the delay of the malicious authoritative answers can force Unbound to slowly accumulate pending answers for the spoofed addresses. When the authoritative answers become available to Unbound at the same time, Unbound starts serving all the accumulated queries. This results in large-sized, concentrated response bursts to the spoofed addresses.
Unbound itself is not vulnerable for DoS, rather it can be used to take part in a pulsing DoS amplification attack.
Remediation
Install update from vendor's website.