CVE-2024-40640
Usage of non-constant time base64 decoder could lead to leakage of secret key material in vodozemac
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
vodozemac is an open source implementation of Olm and Megolm in pure Rust. 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. 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. This has been patched in commit 734b6c6948d4b2bdee3dd8b4efa591d93a61d272 which has been included in release version 0.7.0. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Low2.9 | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N |
| NVDNVD · Deferred | 3.1 | Low2.9 | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.20% · top 90% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 2.9.
Weakness
Affected products
- affected < 0.7.0
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- crates.iovodozemacGHSA-j8cm-g7r6-hfpq (opens in a new tab)
References (3)
- https://github.com/matrix-org/vodozemac/security/advisories/GHSA-j8cm-g7r6-hfpq (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/matrix-org/vodozemac/commit/734b6c6948d4b2bdee3dd8b4efa591d93a61d272 (opens in a new tab)x_refsource_MISCx_transferred
- https://arxiv.org/abs/2108.04600 (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-j8cm-g7r6-hfpq (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2024-40640)Record last updated .