CVE-2024-40640: Vodozemac Vodozemac's Usage Of Non-constant Time Vulnerability

MODERATE
Advisory Identifier: GHSA-j8cm-g7r6-hfpq
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CVSS 3.7
CWE-208
Published
Advisory Summary

CVE-2024-40640 is a MODERATE (CVSS 3.7) vodozemac's usage of non-constant time vulnerability (CWE-208: Observable Timing Discrepancy) affecting Vodozemac libraries in the crates.io ecosystem. The issue involves vodozemac's usage of non-constant time base64 decoder could lead to leakage of secret key material. Remediation is available by upgrading affected packages to version 0.7.0.

CVE-2024-40640 at a Glance

CVE Identifier CVE-2024-40640
GHSA Identifier GHSA-j8cm-g7r6-hfpq
Severity MODERATE
CVSS v3.1 Base Score 3.7
CWE Classification CWE-208: Observable Timing Discrepancy
Affected Product Vodozemac
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 3.7

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

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

How to Fix CVE-2024-40640

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

vodozemac fixed: 0.7.0 
Upgrade vodozemac to 0.7.0
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 vodozemac

How to Check if You Are Affected

To determine whether your application is affected by CVE-2024-40640, inspect your project dependencies for Vodozemac:

inspect dependencies for vodozemac

Analyze the terminal output to locate any version of Vodozemac in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.7.0), 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-208: Observable Timing Discrepancy, where two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not. In Vodozemac, 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

Versions before 0.7.0 of vodozemac use a non-constant time base64 implementation for importing key material for Megolm group sessions and `PkDecryption` Ed25519 secret keys. This flaw might allow an attacker to infer some information about the secret key material through a side-channel attack. ### Impact The use of a non-constant time base64 implementation might allow an attacker to observe timing variations in the encoding and decoding operations of the secret key material. This could potentially provide insights into the underlying secret key material. The impact of this vulnerability is considered low because exploiting the attacker is required to have access to high precision timing measurements, as well as repeated access to the base64 encoding or decoding processes. Additionally, the estimated leakage amount is bounded and low according to the referenced paper. ### Patches The patch is in commit 734b6c6948d4b2bdee3dd8b4efa591d93a61d272. ### Workarounds None. ### References A detailed description of the precise attack can be found at https://arxiv.org/abs/2108.04600. We kindly thank Soatok for pointing out this research to us. ### For more information If you have any questions or comments about this advisory please email us at [security at matrix.org](mailto:security@matrix.org).

CVE-2024-40640 Affected Vodozemac Versions

1 component(s)
Fixed Versions:
0.7.0
Product / Package Ecosystem Affected Versions Fixed Version
vodozemac
 crates.io
< 0.7.0
0.7.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/matrix-org/vodozemac/security/advisories/GHSA-j8cm-g7r6-hfpq
NVD — CVE-2024-40640 NVD
https://nvd.nist.gov/vuln/detail/CVE-2024-40640
Security Fix Commit FIX COMMIT
https://github.com/matrix-org/vodozemac/commit/734b6c6948d4b2bdee3dd8b4efa591d93a61d272
Security Fix Commit FIX COMMIT
https://github.com/matrix-org/vodozemac/commit/77765dace11266ef9523301624a01265c6e0f790
arxiv.org/abs/2108.04600 WEB
https://arxiv.org/abs/2108.04600
Vodozemac Source Repository REPOSITORY
https://github.com/matrix-org/vodozemac
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2024-0354.html

Frequently Asked Questions

What is CVE-2024-40640?
CVE-2024-40640 is a security vulnerability in Vodozemac involving vodozemac's usage of non-constant time base64 decoder could lead to leakage of secret key material under CWE-208: Observable Timing Discrepancy.
Which Vodozemac versions are affected?
Affected versions include releases prior to 0.7.0 across affected packages: vodozemac.
What version fixes CVE-2024-40640?
Upgrading to 0.7.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is vodozemac affected?
Yes, vodozemac is affected in releases prior to 0.7.0. Upgrade your dependency to 0.7.0 or later.
What is the CVSS score of CVE-2024-40640?
CVE-2024-40640 has a CVSS v3.1 base score of 3.7 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2024-40640?
CVE-2024-40640 is classified under CWE-208: Observable Timing Discrepancy (Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.).
How can I check crates.io dependencies for CVE-2024-40640?
Run the dependency tree command: 'inspect dependencies for vodozemac'. 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-j8cm-g7r6-hfpq",
  "modified" : "2024-11-18T16:26:53Z",
  "published" : "2024-07-17T18:30:55Z",
  "aliases" : [ "CVE-2024-40640" ],
  "summary" : "vodozemac's usage of non-constant time base64 decoder could lead to leakage of secret key material",
  "details" : "Versions before 0.7.0 of vodozemac use a non-constant time base64 implementation for importing key material for Megolm group sessions and `PkDecryption` Ed25519 secret keys. This flaw might allow an attacker to infer some information about the secret key material through a side-channel attack.\n\n### Impact\n\nThe use of a non-constant time base64 implementation might allow an attacker to observe timing variations in the encoding and decoding operations of the secret key material. This could potentially provide insights into the underlying secret key material.\n\nThe impact of this vulnerability is considered low because exploiting the attacker is required to have access to high precision timing measurements, as well as repeated access to the base64 encoding or decoding processes.  Additionally, the estimated leakage amount is bounded and low according to the referenced paper.\n\n### Patches\n\nThe patch is in commit 734b6c6948d4b2bdee3dd8b4efa591d93a61d272.\n\n### Workarounds\nNone.\n\n### References\nA detailed description of the precise attack can be found at https://arxiv.org/abs/2108.04600. We kindly thank Soatok for pointing out this research to us.\n\n### For more information\nIf you have any questions or comments about this advisory please email us at [security at matrix.org](mailto:security@matrix.org).\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "vodozemac"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.7.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/matrix-org/vodozemac/security/advisories/GHSA-j8cm-g7r6-hfpq"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-40640"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/matrix-org/vodozemac/commit/734b6c6948d4b2bdee3dd8b4efa591d93a61d272"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/matrix-org/vodozemac/commit/77765dace11266ef9523301624a01265c6e0f790"
  }, {
    "type" : "WEB",
    "url" : "https://arxiv.org/abs/2108.04600"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/matrix-org/vodozemac"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2024-0354.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-208" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-07-17T18:30:55Z",
    "nvd_published_at" : "2024-07-17T18:15:04Z"
  }
}