{"cve":"CVE-2024-40640","nvd":{"published":"2024-07-17T18:15:04.787","modified":"2026-06-17T07:46:13.353","status":"Deferred","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","score":2.9},"cwes":["CWE-208"],"references":["https://arxiv.org/abs/2108.04600","https://github.com/matrix-org/vodozemac/commit/734b6c6948d4b2bdee3dd8b4efa591d93a61d272","https://github.com/matrix-org/vodozemac/security/advisories/GHSA-j8cm-g7r6-hfpq","https://arxiv.org/abs/2108.04600","https://github.com/matrix-org/vodozemac/commit/734b6c6948d4b2bdee3dd8b4efa591d93a61d272"],"products":[],"source":"nvd","synced_at":"2026-10-19T21:52:42.518321223+00:00"},"epss":{"cve":"CVE-2024-40640","score":0.00201,"percentile":0.09955,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-j8cm-g7r6-hfpq","url":"https://osv.dev/vulnerability/GHSA-j8cm-g7r6-hfpq","summary":"vodozemac's usage of non-constant time base64 decoder could lead to leakage of secret key material","modified":"2026-09-10T03:50:16.794237652Z","packages":[{"ecosystem":"crates.io","name":"vodozemac","purl":"pkg:cargo/vodozemac","ranges":["<0.7.0"],"fixed":["0.7.0"]}]},{"id":"RUSTSEC-2024-0354","url":"https://osv.dev/vulnerability/RUSTSEC-2024-0354","summary":" Usage of non-constant time base64 decoder could lead to leakage of secret key material","modified":"2026-10-12T18:00:07.418792131Z","packages":[{"ecosystem":"crates.io","name":"vodozemac","purl":"pkg:cargo/vodozemac","ranges":[">=0.0.0-0 <0.7.0"],"fixed":["0.7.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}