Cyber Resilience

CVE-2024-45403

Dena H2O 2024-06-18 – 2024-09-04

Published
11 October 2024
Modified
12 November 2024
Patch / advisory
CVSS Score v3.1 3.7
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS Score 0.0066 48th percentile
Risk Priority 34 floored blend · peak EPSS

Summary

CVE-2024-45403 is a low-severity Reachable Assertion (CWE-617) vulnerability in Dena H2O. Its CVSS base score is 3.7 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 48th percentile by exploit likelihood (below the median); 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 SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. When h2o is configured as a reverse proxy and HTTP/3 requests are cancelled by the client, h2o might crash due to an assertion failure. The crash can be…

more

exploited by an attacker to mount a Denial-of-Service attack. By default, the h2o standalone server automatically restarts, minimizing the impact. However, HTTP requests that were served concurrently will still be disrupted. The vulnerability has been addressed in commit 1ed32b2. Users may disable the use of HTTP/3 to mitigate the issue.

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.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-50247Same product: Dena H2O
CVE-2024-45397Same product: Dena H2O
CVE-2024-25622Same product: Dena H2O
CVE-2023-41337Same product: Dena H2O
CVE-2024-45396Same vendor: Dena
CVE-2023-30847Same product: Dena H2O
CVE-2024-56783Shared CWE-617
CVE-2025-8804Shared CWE-617
CVE-2024-39509Shared CWE-617
CVE-2025-59029Shared CWE-617

Affected Assets

dena
h2o
2024-06-18 — 2024-09-04

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation finds reachable assertions during development.

Security engineering principles discourage use of assertions for handling untrusted input.

Validating untrusted inputs structurally prevents attacker data from reaching and triggering assertions.

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 directly prevent unsafe assertions from being coded in reachable paths.

DE.CM-09 partial match
prevents

Runtime monitoring of software can detect assertion-triggered crashes as adverse events.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover and record reachable-assertion flaws before deployment.

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 in development can detect reachable assertions before release, reducing the likelihood of exploitation.

prevents

Secure development lifecycle mandates defensive coding and input validation that prevent reachable assertions from being triggered by untrusted data.

prevents

Application security requirements can specify that assertions must not be reachable from attacker-controlled inputs.

prevents

Secure architecture principles discourage the use of assertions for runtime error handling that an attacker could exploit.

prevents

Secure coding standards explicitly ban the use of assert() or equivalent statements that can be triggered by external input.

References