CVE-2025-27498: AEADs/ascon-aead Plaintext Exposed Vulnerability

MODERATE
Advisory Identifier: GHSA-r38m-44fw-h886
Share
CWE-347
Published
Advisory Summary

CVE-2025-27498 is a MODERATE plaintext exposed vulnerability (CWE-347: Improper Verification of Cryptographic Signature) affecting AEADs/ascon-aead libraries in the crates.io ecosystem. The issue involves plaintext exposed in decrypt_in_place_detached even on tag verification failure. Remediation is available by upgrading affected packages to version 0.4.3.

CVE-2025-27498 at a Glance

CVE Identifier CVE-2025-27498
GHSA Identifier GHSA-r38m-44fw-h886
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-347: Improper Verification of Cryptographic Signature
Affected Product AEADs/ascon-aead
Package Ecosystem crates.io
Published Date
Last Updated

How to Fix CVE-2025-27498

To remediate this vulnerability, upgrade all affected AEADs/ascon-aead dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

ascon_aead fixed: 0.4.3 
Upgrade ascon_aead to 0.4.3
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for ascon_aead

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-27498, inspect your project dependencies for AEADs/ascon-aead:

inspect dependencies for ascon_aead

Analyze the terminal output to locate any version of AEADs/ascon-aead in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.4.3), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-347: Improper Verification of Cryptographic Signature, where the product does not verify, or incorrectly verifies, the cryptographic signature for data. In AEADs/ascon-aead, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary In `decrypt_in_place_detached`, the decrypted ciphertext (which is the correct ciphertext) is exposed even if the tag is incorrect. ### Details This is because in [decrypt_inplace](https://github.com/RustCrypto/AEADs/blob/8cda109f1128c4c7953a0bb0f53e1056d537e462/ascon-aead/src/asconcore.rs#L350-L364) in asconcore.rs, tag verification causes an error to be returned with the plaintext contents still in `buffer`. The root cause of this vulnerability is similar to https://github.com/RustCrypto/AEADs/security/advisories/GHSA-423w-p2w9-r7vq ### PoC ```rust use ascon_aead::Tag; use ascon_aead::{Ascon128, Key, Nonce}; use ascon_aead::aead::{AeadInPlace, KeyInit}; fn main() { let key = Key::<Ascon128>::from_slice(b"very secret key."); let cipher = Ascon128::new(key); let nonce = Nonce::<Ascon128>::from_slice(b"unique nonce 012"); // 128-bits; unique per message let mut buffer: Vec<u8> = Vec::new(); // Buffer needs 16-bytes overhead for authentication tag buffer.extend_from_slice(b"plaintext message"); // Encrypt `buffer` in-place detached, replacing the plaintext contents with ciphertext cipher.encrypt_in_place_detached(nonce, b"", &mut buffer).expect("encryption failure!"); // Decrypt `buffer` in-place with the wrong tag, ignoring the decryption error let _ = cipher.decrypt_in_place_detached(nonce, b"", &mut buffer, Tag::<Ascon128>::from_slice(b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00")); assert_eq!(&buffer, b"plaintext message"); } ``` ### Impact If a program continues to use the result of `decrypt_in_place_detached` after a decryption failure, the result will be unauthenticated. This may permit some forms of chosen ciphertext attacks (CCAs).

CVE-2025-27498 Affected AEADs/ascon-aead Versions

1 component(s)
Fixed Versions:
0.4.3
Product / Package Ecosystem Affected Versions Fixed Version
ascon_aead
 crates.io
< 0.4.3
0.4.3

References

GitHub Advisory / Wiki ADVISORY
https://github.com/RustCrypto/AEADs/security/advisories/GHSA-r38m-44fw-h886
NVD — CVE-2025-27498 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-27498
Security Fix Commit FIX COMMIT
https://github.com/RustCrypto/AEADs/commit/d1d749ba57e38e65b0e037cd744d0b17f7254037
AEADs/ascon-aead Source Repository REPOSITORY
https://github.com/RustCrypto/AEADs

Frequently Asked Questions

What is CVE-2025-27498?
CVE-2025-27498 is a security vulnerability in AEADs/ascon-aead involving Plaintext exposed in decrypt_in_place_detached even on tag verification failure under CWE-347: Improper Verification of Cryptographic Signature.
Which AEADs/ascon-aead versions are affected?
Affected versions include releases prior to 0.4.3 across affected packages: ascon_aead.
What version fixes CVE-2025-27498?
Upgrading to 0.4.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is ascon_aead affected?
Yes, ascon_aead is affected in releases prior to 0.4.3. Upgrade your dependency to 0.4.3 or later.
What CWE is associated with CVE-2025-27498?
CVE-2025-27498 is classified under CWE-347: Improper Verification of Cryptographic Signature (The product does not verify, or incorrectly verifies, the cryptographic signature for data.).
How can I check crates.io dependencies for CVE-2025-27498?
Run the dependency tree command: 'inspect dependencies for ascon_aead'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-r38m-44fw-h886",
  "modified" : "2025-03-03T20:22:19Z",
  "published" : "2025-03-03T20:22:19Z",
  "aliases" : [ "CVE-2025-27498" ],
  "summary" : "AEADs/ascon-aead: Plaintext exposed in decrypt_in_place_detached even on tag verification failure",
  "details" : "### Summary\nIn `decrypt_in_place_detached`, the decrypted ciphertext (which is the correct ciphertext) is exposed even if the tag is incorrect.\n\n### Details\nThis is because in [decrypt_inplace](https://github.com/RustCrypto/AEADs/blob/8cda109f1128c4c7953a0bb0f53e1056d537e462/ascon-aead/src/asconcore.rs#L350-L364) in asconcore.rs, tag verification causes an error to be returned with the plaintext contents still in `buffer`. The root cause of this vulnerability is similar to https://github.com/RustCrypto/AEADs/security/advisories/GHSA-423w-p2w9-r7vq\n\n### PoC\n```rust\nuse ascon_aead::Tag;\nuse ascon_aead::{Ascon128, Key, Nonce};\nuse ascon_aead::aead::{AeadInPlace, KeyInit};\n\nfn main() {\n\n    let key = Key::<Ascon128>::from_slice(b\"very secret key.\");\n    let cipher = Ascon128::new(key);\n\n    let nonce = Nonce::<Ascon128>::from_slice(b\"unique nonce 012\"); // 128-bits; unique per message\n\n    let mut buffer: Vec<u8> = Vec::new(); // Buffer needs 16-bytes overhead for authentication tag\n    buffer.extend_from_slice(b\"plaintext message\");\n\n    // Encrypt `buffer` in-place detached, replacing the plaintext contents with ciphertext\n    cipher.encrypt_in_place_detached(nonce, b\"\", &mut buffer).expect(\"encryption failure!\");\n    \n    // Decrypt `buffer` in-place with the wrong tag, ignoring the decryption error\n    let _ = cipher.decrypt_in_place_detached(nonce, b\"\", &mut buffer, Tag::<Ascon128>::from_slice(b\"\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\"));\n\n    assert_eq!(&buffer, b\"plaintext message\");\n}\n```\n### Impact\nIf a program continues to use the result of `decrypt_in_place_detached` after a decryption failure, the result will be unauthenticated. This may permit some forms of chosen ciphertext attacks (CCAs).",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "ascon_aead"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.4.3"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.4.2"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/RustCrypto/AEADs/security/advisories/GHSA-r38m-44fw-h886"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-27498"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/RustCrypto/AEADs/commit/d1d749ba57e38e65b0e037cd744d0b17f7254037"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/RustCrypto/AEADs"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-347" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-03-03T20:22:19Z",
    "nvd_published_at" : "2025-03-03T17:15:16Z"
  }
}