Uninitialized memory exposure in claxon

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

EPSS

• CVE-2018-20992: 1.37% estimated exploitation activity in the next 30 days; percentile 71.99 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Affected versions of Claxon made an invalid assumption about the decode buffer size being a multiple of a value read from the bitstream. This could cause parts of the decode buffer to not be overwritten. If the decode buffer was newly allocated and uninitialized, this uninitialized memory could be exposed. This allows an attacker to observe parts of the uninitialized memory in the decoded audio stream. The flaw was corrected by checking that the value read from the bitstream divides the decode buffer size, and returning a format error if it does not. If an error is returned, the decode buffer is not exposed. Regression tests and an additional fuzzer have been added to prevent similar flaws in the future.

Published by the source

25 Aug 2021, 20:43 UTC

Last modified by the source

13 Jun 2023, 16:57 UTC

Source last checked

26 Oct 2026, 15:33 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8c6g-4xc5-w96c

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# Patch Next advisory brief: CVE-2018-20992

Advisory: Uninitialized memory exposure in claxon
IDs: CVE-2018-20992, GHSA-8c6g-4xc5-w96c
Record: https://patchnext.com/advisories/cve-2018-20992 (revision 1, source checked 26 Oct 2026, 15:33 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: claxon 0.4.1, 0.3.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io claxon: affected >= 0.4.0, < 0.4.1; < 0.3.2; fixed in 0.3.2, 0.4.1

## Suggested inspection (read-only)
- crates.io claxon: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on claxon.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-8c6g-4xc5-w96c (GitHub-reviewed advisory GHSA-8c6g-4xc5-w96c lists affected ranges: crates.io claxon >=0.4.0 =0 <0.3.2)

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