GHSA-9763-4f94-gfch: CIRCL's Kyber Timing Side-channel (kyberslash2) Vulnerability

HIGH
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Advisory Summary

GHSA-9763-4f94-gfch is a HIGH timing side-channel (kyberslash2) vulnerability (General Security Weakness) affecting CIRCL's Kyber libraries in the Go ecosystem. The issue involves timing side-channel (kyberslash2). Remediation is available by upgrading affected packages to version 1.3.7.

GHSA-9763-4f94-gfch at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-9763-4f94-gfch
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification General Security Weakness
Affected Product CIRCL's Kyber
Package Ecosystem Go
Published Date
Last Updated

How to Fix GHSA-9763-4f94-gfch

To remediate this vulnerability, upgrade all affected CIRCL's Kyber dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/cloudflare/circl fixed: 1.3.7 
Upgrade github.com/cloudflare/circl to 1.3.7
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 github.com/cloudflare/circl

How to Check if You Are Affected

To determine whether your application is affected by GHSA-9763-4f94-gfch, inspect your project dependencies for CIRCL's Kyber:

inspect dependencies for github.com/cloudflare/circl

Analyze the terminal output to locate any version of CIRCL's Kyber in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.3.7), 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 General Security Weakness. In CIRCL's Kyber, 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

### Impact On some platforms, when an attacker can time decapsulation of Kyber on forged cipher texts, they could possibly learn (parts of) the secret key. Does not apply to ephemeral usage, such as when used in the regular way in TLS. ### Patches Patched in 1.3.7. ### References - [kyberslash.cr.yp.to](https://kyberslash.cr.yp.to/)

GHSA-9763-4f94-gfch Affected CIRCL's Kyber Versions

1 component(s)
Fixed Versions:
1.3.7
Product / Package Ecosystem Affected Versions Fixed Version
github.com/cloudflare/circl
golang/github.com/cloudflare/circl
Go
< 1.3.7
1.3.7

References

GitHub Advisory / Wiki ADVISORY
https://github.com/cloudflare/circl/security/advisories/GHSA-9763-4f94-gfch
Security Fix Commit FIX COMMIT
https://github.com/cloudflare/circl/commit/75ef91e8a2f438e6ce2b6e620d236add8be1887d
CIRCL's Kyber Source Repository REPOSITORY
https://github.com/cloudflare/circl
kyberslash.cr.yp.to WEB
https://kyberslash.cr.yp.to

Frequently Asked Questions

What is GHSA-9763-4f94-gfch?
GHSA-9763-4f94-gfch is a security vulnerability in CIRCL's Kyber involving timing side-channel (kyberslash2) under General Security Weakness.
Which CIRCL's Kyber versions are affected?
Affected versions include releases prior to 1.3.7 across affected packages: github.com/cloudflare/circl.
What version fixes GHSA-9763-4f94-gfch?
Upgrading to 1.3.7 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/cloudflare/circl affected?
Yes, github.com/cloudflare/circl is affected in releases prior to 1.3.7. Upgrade your dependency to 1.3.7 or later.
What CWE is associated with GHSA-9763-4f94-gfch?
GHSA-9763-4f94-gfch is classified under General Security Weakness.
How can I check Go dependencies for GHSA-9763-4f94-gfch?
Run the dependency tree command: 'inspect dependencies for github.com/cloudflare/circl'. 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-9763-4f94-gfch",
  "modified" : "2024-05-20T22:00:44Z",
  "published" : "2024-01-08T16:45:05Z",
  "aliases" : [ ],
  "summary" : "CIRCL's Kyber: timing side-channel (kyberslash2)",
  "details" : "### Impact\nOn some platforms, when an attacker can time decapsulation of Kyber on forged cipher texts, they could possibly learn (parts of) the secret key.\n\nDoes not apply to ephemeral usage, such as when used in the regular way in TLS.\n\n### Patches\nPatched in 1.3.7.\n\n### References\n- [kyberslash.cr.yp.to](https://kyberslash.cr.yp.to/)",
  "severity" : [ ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/cloudflare/circl"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.3.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/cloudflare/circl/security/advisories/GHSA-9763-4f94-gfch"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cloudflare/circl/commit/75ef91e8a2f438e6ce2b6e620d236add8be1887d"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/cloudflare/circl"
  }, {
    "type" : "WEB",
    "url" : "https://kyberslash.cr.yp.to"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-01-08T16:45:05Z",
    "nvd_published_at" : null
  }
}