CVE-2019-25005: Chacha20 Counter Overflow Vulnerability

HIGH
Advisory Identifier: GHSA-j2r6-2m5c-vgh5
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CVSS 7.5
CWE-190
Published
Advisory Summary

CVE-2019-25005 is a HIGH (CVSS 7.5) counter overflow vulnerability (CWE-190: Integer Overflow or Wraparound) affecting Chacha20 libraries in the crates.io ecosystem. The issue involves counter overflow in chacha20. Remediation is available by upgrading affected packages to version 0.2.3.

CVE-2019-25005 at a Glance

CVE Identifier CVE-2019-25005
GHSA Identifier GHSA-j2r6-2m5c-vgh5
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-190: Integer Overflow or Wraparound
Affected Product Chacha20
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2019-25005

To remediate this vulnerability, upgrade all affected Chacha20 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

chacha20 fixed: 0.2.3 
Upgrade chacha20 to 0.2.3
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 chacha20

How to Check if You Are Affected

To determine whether your application is affected by CVE-2019-25005, inspect your project dependencies for Chacha20:

inspect dependencies for chacha20

Analyze the terminal output to locate any version of Chacha20 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.2.3), 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-190: Integer Overflow or Wraparound, where the product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. this occurs when an integer value is incremented to a value that is too large to store in the associated representation. when this occurs, the value may become a very small or negative number. In Chacha20, 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

An issue was discovered in the chacha20 crate before 0.2.3 for Rust. A ChaCha20 counter overflow makes it easier for attackers to determine plaintext.

CVE-2019-25005 Affected Chacha20 Versions

1 component(s)
Fixed Versions:
0.2.3
Product / Package Ecosystem Affected Versions Fixed Version
chacha20
 crates.io
< 0.2.3
0.2.3

References

NVD — CVE-2019-25005 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-25005
Chacha20 Source Repository REPOSITORY
https://github.com/RustCrypto/stream-ciphers/pull/64
Chacha20 Source Repository REPOSITORY
https://github.com/RustCrypto/stream-ciphers/tree/master/chacha20
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2019-0029.html

Frequently Asked Questions

What is CVE-2019-25005?
CVE-2019-25005 is a security vulnerability in Chacha20 involving Counter overflow in chacha20 under CWE-190: Integer Overflow or Wraparound.
Which Chacha20 versions are affected?
Affected versions include releases prior to 0.2.3 across affected packages: chacha20.
What version fixes CVE-2019-25005?
Upgrading to 0.2.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is chacha20 affected?
Yes, chacha20 is affected in releases prior to 0.2.3. Upgrade your dependency to 0.2.3 or later.
What is the CVSS score of CVE-2019-25005?
CVE-2019-25005 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2019-25005?
CVE-2019-25005 is classified under CWE-190: Integer Overflow or Wraparound (The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.).
How can I check crates.io dependencies for CVE-2019-25005?
Run the dependency tree command: 'inspect dependencies for chacha20'. 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-j2r6-2m5c-vgh5",
  "modified" : "2021-08-19T21:20:52Z",
  "published" : "2021-08-25T20:45:20Z",
  "aliases" : [ "CVE-2019-25005" ],
  "summary" : "Counter overflow in chacha20",
  "details" : "An issue was discovered in the chacha20 crate before 0.2.3 for Rust. A ChaCha20 counter overflow makes it easier for attackers to determine plaintext.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "chacha20"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.2.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-25005"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/RustCrypto/stream-ciphers/pull/64"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/RustCrypto/stream-ciphers/tree/master/chacha20"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2019-0029.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-190" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-19T21:20:52Z",
    "nvd_published_at" : null
  }
}