rustsec-2026-0239
Vulnerability from osv_rustsec
Published
2026-08-09 12:00
Modified
2026-08-09 12:34
Summary
Streaming AEAD does not authenticate stream structure
Details

In all published versions of dcrypt-symmetric before 2.0.0, version-1 GCM and ChaCha20-Poly1305 streams used unauthenticated terminator, counter, and length fields. Decryptors trusted transmitted counters, allocated from unbounded lengths, and discarded plaintext that did not fit a caller's single read buffer. An attacker could obtain successful truncated EOF, omit, replay, or reorder frames within a stream, or request an allocation approaching 4 GiB.

Version 2.0.0 introduces the DCRSTRM2 format, which authenticates its version, algorithm, random stream identifier, base nonce, strict sequence, bounded lengths, final flag, and caller AAD. It enforces authenticated finality and physical EOF, bounds frames to 16 KiB before allocation, retains partial-read plaintext, and rejects legacy version-1 input. Existing version-1 ciphertext cannot retrospectively prove completeness or ordering and must be migrated only through an application-specific, explicitly trusted process.

References
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "categories": [
          "crypto-failure",
          "denial-of-service"
        ],
        "cvss": null,
        "informational": null
      },
      "ecosystem_specific": {
        "affected_functions": null,
        "affects": {
          "arch": [],
          "functions": [],
          "os": []
        }
      },
      "package": {
        "ecosystem": "crates.io",
        "name": "dcrypt-symmetric",
        "purl": "pkg:cargo/dcrypt-symmetric"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.0.0-0"
            },
            {
              "fixed": "2.0.0"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "versions": []
    }
  ],
  "aliases": [
    "GHSA-8cwp-4826-jg9f"
  ],
  "database_specific": {
    "license": "CC0-1.0"
  },
  "details": "In all published versions of `dcrypt-symmetric` before 2.0.0, version-1 GCM and\nChaCha20-Poly1305 streams used unauthenticated terminator, counter, and length\nfields. Decryptors trusted transmitted counters, allocated from unbounded\nlengths, and discarded plaintext that did not fit a caller\u0027s single read\nbuffer. An attacker could obtain successful truncated EOF, omit, replay, or\nreorder frames within a stream, or request an allocation approaching 4 GiB.\n\nVersion 2.0.0 introduces the `DCRSTRM2` format, which authenticates its version,\nalgorithm, random stream identifier, base nonce, strict sequence, bounded\nlengths, final flag, and caller AAD. It enforces authenticated finality and\nphysical EOF, bounds frames to 16 KiB before allocation, retains partial-read\nplaintext, and rejects legacy version-1 input. Existing version-1 ciphertext\ncannot retrospectively prove completeness or ordering and must be migrated only\nthrough an application-specific, explicitly trusted process.",
  "id": "RUSTSEC-2026-0239",
  "modified": "2026-08-09T12:34:06Z",
  "published": "2026-08-09T12:00:00Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://crates.io/crates/dcrypt-symmetric"
    },
    {
      "type": "ADVISORY",
      "url": "https://rustsec.org/advisories/RUSTSEC-2026-0239.html"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/ioi-foundation/dcrypt/security/advisories/GHSA-8cwp-4826-jg9f"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ioi-foundation/dcrypt/commit/c99cc86f0ee353010cd202cbcd2c310371b0bbb8"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ioi-foundation/dcrypt/releases/tag/v2.0.0"
    }
  ],
  "related": [],
  "severity": [],
  "summary": "Streaming AEAD does not authenticate stream structure"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.