CVE-2024-8508: debian debian_linux Unchecked Input for Loop Condition

Vulnerability summary

CVE-2024-8508 is a medium (CVSS 5.3) Unchecked Input for Loop Condition vulnerability in debian debian_linux. EPSS estimates a 0.80% chance of exploitation in the next 30 days, higher than 55.8% of scored vulnerabilities.

Timeline

1. 03-10-2024
   PublishedVulnerability first disclosed.
2. 14-11-2024
   Last modifiedVulnerability information updated.

Description

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.

• CWE-606Unchecked Input for Loop ConditionThe product does not properly check inputs that are used for loop conditions, potentially leading to a denial of service or other consequences because of excessive looping.
• CWE-1284Improper Validation of Specified Quantity in InputThe product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.