AEADs/ascon-aead: Plaintext exposed in decrypt_in_place_detached even on tag verification failure

published 2025-03-03 last yr. modified 2026-06-17 4mo ago also EUVD-2025-5557 , GHSA-r38m-44fw-h886

cvss: 5.7; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.1%; EPSS 0.1% chance of exploitation in 30 days, percentile 2%
public exploits: 0; none known

aes-gcm is a pure Rust implementation of the AES-GCM. In decrypt_in_place_detached, the decrypted ciphertext (which is the correct ciphertext) is exposed even if the tag is incorrect. This is because in decrypt_inplace in asconcore.rs, tag verification causes an error to be returned with the plaintext contents still in buffer. The vulnerability is fixed in 0.4.3.

Patch / fix

fixed in 2 links 1

crates.io ascon_aead 0.4.3
aes-gcm_project aes-gcm 0.4.3

github.com/RustCrypto/AEADs@d1d749b commit

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CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: last yr. (2025-03-03)

Exploit prediction

0.13% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.6	CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:A/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N
CNA	4.0	5.7	CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:A/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem	package	affected	fixed in
crates.io	ascon_aead	<0.4.3	0.4.3

Affected products

RustCrypto AEADs

Classification

Weakness

CWE-347 Improper Verification of Cryptographic Signature

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

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