Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2024-1931 is a high-severity Infinite Loop (CWE-835) vulnerability in Fedoraproject Fedora. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked in the top 15% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-2 (Flaw Remediation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
NLnet Labs Unbound versions 1.18.0 through 1.19.1 contain an infinite-loop flaw (CWE-835) that produces a denial of service. The defect was introduced when support for Extended DNS Error (EDE) records was added; before stripping EDE records that exceed a client’s advertised UDP buffer size, the code attempts to trim the accompanying text fields while preserving the EDE codes. An unchecked condition in this trimming routine causes unbounded looping when Unbound generates a positive response containing EDE information and the client buffer is smaller than required. The issue is reachable only when the non-default “ede: yes” configuration option is enabled.
An unauthenticated remote attacker can trigger the loop by sending a query that elicits such a response, resulting in a persistent denial of service (CVSS 7.5). Because the vulnerable code path lies in Unbound’s reply-generation logic, exploitation requires only network reachability to a configured resolver and does not depend on crafted DNSSEC material or other special query features.
Upstream corrected the flaw in Unbound 1.19.2. Distribution advisories for Fedora and FreeBSD, together with NetApp’s security bulletin, recommend upgrading to the patched release or disabling the ede option as immediate mitigations. The EPSS score has remained flat at 0.0675 with no observed increase after disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-17653
Vulnerability Data
NLnet Labs Unbound version 1.18.0 up to and including version 1.19.1 contain a vulnerability that can cause denial of service by a certain code path that can lead to an infinite loop. Unbound 1.18.0 introduced a feature that removes EDE…
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records from responses with size higher than the client's advertised buffer size. Before removing all the EDE records however, it would try to see if trimming the extra text fields on those records would result in an acceptable size while still retaining the EDE codes. Due to an unchecked condition, the code that trims the text of the EDE records could loop indefinitely. This happens when Unbound would reply with attached EDE information on a positive reply and the client's buffer size is smaller than the needed space to include EDE records. The vulnerability can only be triggered when the 'ede: yes' option is used; non default configuration. From version 1.19.2 on, the code is fixed to avoid looping indefinitely.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover unreachable loop exit conditions through static analysis, fuzzing, or execution tracing.
Flaw remediation processes identify and correct infinite-loop defects reported from testing or operations.
Requiring documented development processes and secure coding standards reduces introduction of loops whose termination conditions are unreachable.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.