Cyber Resilience

CVE-2024-1931

DoS in Fedoraproject Fedora 38 … 40

Published
07 March 2024
Modified
17 June 2026
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.025 83th percentile
Risk Priority 65 floored blend · peak EPSS

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 Application or System Exploitation (T1499.004); ranked in the top 17% 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

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…

more

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

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-4854Same product: Fedoraproject Fedora
CVE-2023-20197Same product: Fedoraproject Fedora
CVE-2023-3255Same product: Fedoraproject Fedora
CVE-2023-34966Same product: Fedoraproject Fedora
CVE-2024-1622Same product: Fedoraproject Fedora
CVE-2026-42923Same product: Nlnetlabs Unbound
CVE-2026-55717Same product: Nlnetlabs Unbound
CVE-2026-44390Same product: Nlnetlabs Unbound
CVE-2026-44621Same product: Nlnetlabs Unbound
CVE-2026-41292Same product: Nlnetlabs Unbound

Affected Assets

nlnetlabs
unbound
1.18.0 — 1.19.2
fedoraproject
fedora
38, 39, 40

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices (reviews, testing, static analysis) directly prevent introduction of infinite-loop defects.

ID.RA-01 partial match
prevents

Static analysis and vuln scanning during asset assessment can detect unreachable loop exits.

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.

finds

Security testing can uncover infinite-loop conditions before release.

prevents

Secure development life cycle mandates practices that can detect and prevent infinite-loop defects.

prevents

Application security requirements can specify loop-termination rules, indirectly reducing the weakness.

prevents

Secure coding standards directly address loop termination and prevent infinite loops.

none

Secure architecture principles encourage designs that avoid unreachable exit conditions.

none

Change management can require review of loop logic when code is modified.

References