CVE-2024-40640 LOW

CVE-2024-40640: Usage of non-constant time base64 decoder could lead to leakage of secret key material in vodozemac

Vendor Matrix-Org
Product vodozemac
Weakness CWE-208
Published July 17, 2024
Last update August 2, 2024

CVSS base score

2.9/10
Attack vector Local
Attack complexity High
Privileges required None
User interaction None
Confidentiality Low
Integrity None

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

July 17, 2024 CVE published
August 2, 2024 Record updated