AEADs/aes-gcm: Plaintext exposed in decrypt_in_place_detached even on tag verification failure

Exploitation

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

CVSS

4.7 · CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:H/A:N

EPSS

• CVE-2023-42811: 0.23% estimated exploitation activity in the next 30 days; percentile 13.92 (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.

Summary In the AES GCM implementation of decryptinplacedetached, the decrypted ciphertext (i.e. the correct plaintext) is exposed even if tag verification fails. Impact If a program using the aes-gcm crate's decryptinplace APIs accesses the buffer after decryption failure, it will contain a decryption of an unauthenticated input. Depending on the specific nature of the program this may enable Chosen Ciphertext Attacks (CCAs) which can cause a catastrophic breakage of the cipher including full plaintext recovery. Details As seen in the implementation of decryptinplacedetached for AES GCM, if the tag verification fails, an error is returned. Because the decryption of the ciphertext is done in place, the plaintext contents are now exposed via buffer. This should ideally not be the case - as noted in page 17 of NIST's publication Recommendation for Block Cipher Modes of Operation: Galois/Counter Mode (GCM) and GMAC: In Step 8, the result of Step 7 is compared with the authentication tag…

Published by the source

22 Sep 2023, 16:11 UTC

Last modified by the source

31 Dec 2025, 22:00 UTC

Source last checked

26 Oct 2026, 15:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-423w-p2w9-r7vq

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# Patch Next advisory brief: CVE-2023-42811

Advisory: AEADs/aes-gcm: Plaintext exposed in decrypt_in_place_detached even on tag verification failure
IDs: CVE-2023-42811, GHSA-423w-p2w9-r7vq
Record: https://patchnext.com/advisories/cve-2023-42811 (revision 1, source checked 26 Oct 2026, 15:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: aes-gcm 0.10.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io aes-gcm: affected >= 0.10.0, <= 0.10.2; fixed in 0.10.3

## Suggested inspection (read-only)
- crates.io aes-gcm: 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 aes-gcm.
- 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-423w-p2w9-r7vq (GitHub-reviewed advisory GHSA-423w-p2w9-r7vq lists affected ranges: crates.io aes-gcm >=0.10.0 <=0.10.2)

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