CVE-2021-24119
Publication date 14 July 2021
Last updated 11 July 2025
Ubuntu priority
Description
In Trusted Firmware Mbed TLS 2.24.0, a side-channel vulnerability in base64 PEM file decoding allows system-level (administrator) attackers to obtain information about secret RSA keys via a controlled-channel and side-channel attack on software running in isolated environments that can be single stepped, especially Intel SGX.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| mbedtls | 25.10 questing |
Needs evaluation
|
| 25.04 plucky |
Needs evaluation
|
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 16.04 LTS xenial |
Needs evaluation
|
|
| 14.04 LTS trusty | Not in release | |
| polarssl | 25.10 questing | Not in release |
| 25.04 plucky | Not in release | |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release | |
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Ignored end of standard support | |
| 14.04 LTS trusty | Not in release |
Notes
seth-arnold
It looks like an entire new class of side-channel-free functions was introduced in newer versions of mbedtls; backporting all of them probably doesn't make sense, this fix only makes sense in context of trying to provide constant-time execution that limits side-channel bandwidth to adversaries on the same machine.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
4.9 · Medium
|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | High |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | None |
| Availability impact | None |
| Vector | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N |