RUSTSEC-2023-0079 (GHSA-X5J2-G63M-F8G4)
Vulnerability from osv_rustsec – Published: 2023-12-01 12:00 – Updated: 2024-04-12 21:07 – Source websiteVarious Kyber software libraries in various environments leak secret information into timing, specifically because
- these libraries include a line of code that divides a secret numerator by a public denominator,
- the number of CPU cycles for division in various environments varies depending on the inputs to the division, and
- this variation appears within the range of numerators used in these libraries.
The KyberSlash pages track which Kyber libraries have this issue, and include a FAQ about the issue.
Author
The KyberSlash pages were written by Daniel J. Bernstein. The FAQ originally said "I", but some people seemed to have trouble finding this authorship statement, so the FAQ now says "Bernstein" instead.
URL
The permanent link for the KyberSlash pages is https://kyberslash.cr.yp.to.
Mitigation status in pqc_kyber crate
The issue has not been resolved in the upstream pqc_kyber crate.
A third-party fork that mitigates this attack vector has been published as safe_pqc_kyber.
Alternatives
The ml-kem crate is a maintained
alternative pure Rust implementation of ML-KEM / Kyber.
{
"affected": [
{
"database_specific": {
"categories": [
"crypto-failure"
],
"cvss": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
"informational": null
},
"ecosystem_specific": {
"affected_functions": null,
"affects": {
"arch": [],
"functions": [],
"os": []
}
},
"package": {
"ecosystem": "crates.io",
"name": "pqc_kyber",
"purl": "pkg:cargo/pqc_kyber"
},
"ranges": [
{
"events": [
{
"introduced": "0.0.0-0"
}
],
"type": "SEMVER"
}
],
"versions": []
}
],
"aliases": [
"GHSA-x5j2-g63m-f8g4"
],
"database_specific": {
"license": "CC0-1.0"
},
"details": "Various Kyber software libraries in various environments leak secret information into timing, specifically because\n\n * these libraries include a line of code that divides a secret numerator by a public denominator,\n * the number of CPU cycles for division in various environments varies depending on the inputs to the division, and\n * this variation appears within the range of numerators used in these libraries.\n\nThe KyberSlash pages track which Kyber [libraries](https://kyberslash.cr.yp.to/libraries.html) have this issue, and include a [FAQ](https://kyberslash.cr.yp.to/faq.html) about the issue.\n\n## Author\n\nThe KyberSlash pages were written by Daniel J. Bernstein. The FAQ originally said \"I\", but some people seemed to have trouble finding this authorship statement, so the FAQ now says \"Bernstein\" instead.\n\n## URL\n\nThe permanent link for the KyberSlash pages is [https://kyberslash.cr.yp.to](https://kyberslash.cr.yp.to).\n\n## Mitigation status in `pqc_kyber` crate\n\nThe issue has not been resolved in the upstream `pqc_kyber` crate.\n\nA third-party fork that mitigates this attack vector has been published as [`safe_pqc_kyber`](https://crates.io/crates/safe_pqc_kyber).\n\n## Alternatives\n\nThe [`ml-kem`](https://crates.io/crates/ml-kem) crate is a maintained\nalternative pure Rust implementation of ML-KEM / Kyber.",
"id": "RUSTSEC-2023-0079",
"modified": "2024-04-12T21:07:31Z",
"published": "2023-12-01T12:00:00Z",
"references": [
{
"type": "PACKAGE",
"url": "https://crates.io/crates/pqc_kyber"
},
{
"type": "ADVISORY",
"url": "https://rustsec.org/advisories/RUSTSEC-2023-0079.html"
},
{
"type": "REPORT",
"url": "https://github.com/Argyle-Software/kyber/issues/108"
},
{
"type": "WEB",
"url": "https://kyberslash.cr.yp.to/faq.html"
},
{
"type": "WEB",
"url": "https://kyberslash.cr.yp.to/libraries.html"
},
{
"type": "WEB",
"url": "https://github.com/bwesterb/argyle-kyber/commit/b5c6ad13f4eece80e59c6ebeafd787ba1519f5f6"
}
],
"related": [],
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "KyberSlash: division timings depending on secrets"
}
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Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
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- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
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- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
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