CVE-2024-8508: Unbounded name compression could lead to Denial of Service
Last updated 23 October 2024
Other sources
NLnet Labs Unbound up to and including version 1.21.0 contains a vulnerability when handling replies with very large RRsets that it needs to perform name compression for. Malicious upstreams responses with very large RRsets can cause Unbound to spend a considerable time applying name compression to downstream replies. This can lead to degraded performance and eventually denial of service in well orchestrated attacks. The vulnerability can be exploited by a malicious actor querying Unbound for the specially crafted contents of a malicious zone with very large RRsets. Before Unbound replies to the query it will try to apply name compression which was an unbounded operation that could lock the CPU until the whole packet was complete. Unbound version 1.21.1 introduces a hard limit on the number of name compression calculations it is willing to do per packet. Packets that need more compression will result in semi-compressed packets or truncated packets, even on TCP for huge messages, to avoid locking the CPU for long. This change should not affect normal DNS traffic.
— NVD
Unbounded name compression could lead to Denial of Service
— Microsoft
Affected Software
Remediation
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Event History
Frequently Asked Questions
What is the severity of CVE-2024-8508?
CVE-2024-8508 is considered a moderate severity vulnerability due to its potential impact on system performance.
How do I fix CVE-2024-8508?
To mitigate CVE-2024-8508, upgrade Unbound to version 1.22.0-1 or later.
What software is affected by CVE-2024-8508?
CVE-2024-8508 affects NLnet Labs Unbound versions up to and including 1.21.0.
What type of vulnerability is CVE-2024-8508?
CVE-2024-8508 is a denial of service vulnerability that arises from handling large RRsets.
Who is responsible for the CVE-2024-8508 vulnerability?
The CVE-2024-8508 vulnerability was discovered in the NLnet Labs Unbound software.