Summary
The UserIdentity::is_verified() method in the matrix-sdk-crypto crate before version 0.7.2 doesn't take into account the verification status of the user's own identity while performing the check and may as a result return a value contrary to what is implied by its name and documentation.
Workarounds
None.
Impact
If the method is used to decide whether to perform sensitive operations towards a user identity, a malicious homeserver could manipulate the outcome in order to make the identity appear trusted. This is not a typical usage of the method, which lowers the impact. The method itself is not used inside the matrix-sdk-crypto crate.
The application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.
CVE-2024-40648 has a CVSS score of 4.8 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.7.2); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
The 0.7.2 release of the matrix-sdk-crypto crate includes a fix.
Frequently Asked Questions
- What is CVE-2024-40648? CVE-2024-40648 is a medium-severity improper authentication vulnerability in matrix-sdk-crypto (rust), affecting versions < 0.7.2. It is fixed in 0.7.2. The application does not adequately verify the identity of a user, device, or process before granting access.
- How severe is CVE-2024-40648? CVE-2024-40648 has a CVSS score of 4.8 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of matrix-sdk-crypto are affected by CVE-2024-40648? matrix-sdk-crypto (rust) versions < 0.7.2 is affected.
- Is there a fix for CVE-2024-40648? Yes. CVE-2024-40648 is fixed in 0.7.2. Upgrade to this version or later.
- Is CVE-2024-40648 exploitable, and should I be worried? Whether CVE-2024-40648 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2024-40648 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2024-40648? Upgrade
matrix-sdk-cryptoto 0.7.2 or later.