RUSTSEC-2024-0354: Usage of non-constant time base64 decoder could lead to leakage of secret key material

What to do

1. See which version you have: cargo tree -i vodozemac (it also shows which of your dependencies pulls it in).
2. Update within your version requirement: cargo update -p vodozemac. If the fix is a newer major or minor than your requirement allows, raise it in Cargo.toml (for example vodozemac = "0.7.0") or update the dependency that pulls it in.
3. Check again with cargo audit, or paste your Cargo.lock into our Cargo.toml checker.

Details from the advisory

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[[1]].

References

• Package: crates.io/crates/vodozemac
• Advisory: rustsec.org/advisories/RUSTSEC-2024-0354.html
• Web: github.com/matrix-org/vodozemac/commit/734b6c6948d4b2bdee3dd8b4efa591d93a61d272

From the RustSec Advisory Database (CC0-1.0) via the OSV export, downloaded Oct 24, 2026. Severity score computed from the published CVSS vector.

Other advisories for vodozemac

• VulnerabilityRUSTSEC-2024-0342 · 2024-05-02Degraded secret zeroization capabilities

Full security history of vodozemac