# CVE-2021-24119: Information disclosure in n/a

> System-level attackers can extract secret RSA keys from Mbed TLS via side-channel attacks on base64 decoding in isolated environments like Intel SGX.

- **Severity:** Medium 4.9 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 14 Jul 2021
- **Updated:** 3 Nov 2025
- **Also known as:** DEBIAN-CVE-2021-24119, GHSA-7wc7-36pp-g93m, JLSEC-2025-203, UBUNTU-CVE-2021-24119, openSUSE-SU-2021:1344-1, openSUSE-SU-2021:1355-1, openSUSE-SU-2021:1389-1, openSUSE-SU-2024:11552-1

## What is CVE-2021-24119?

CVE-2021-24119 is a medium-severity vulnerability in Arm Mbed Tls, published on 14 Jul 2021. An attacker needs administrator access to exploit it, with no action from the victim.

### Official 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.

Weakness: CWE-203 (Observable Discrepancy)

## Which versions are affected by CVE-2021-24119?

It affects 3 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mbedtls` | SUSE:Package Hub 15 SP2 | All versions | 2.16.9-bp152.2.6.1 |
| `mbedtls` | SUSE:Package Hub 15 SP3 | All versions | 2.16.9-bp153.2.5.1 |
| `mbedtls` | openSUSE:Leap 15.2 | All versions | 2.16.9-lp152.2.6.1 |
| `mbedtls` | openSUSE:Leap 15.3 | All versions | 2.16.9-bp153.2.5.1 |
| `mbedtls-2` | openSUSE:Tumbleweed | All versions | 2.27.0-2.1 |

Products: Arm Mbed Tls, Debian Debian Linux, Fedoraproject Fedora.

## How do I fix CVE-2021-24119?

Upgrade to a fixed version.

## Is CVE-2021-24119 being exploited?

There is no known exploitation of CVE-2021-24119 in the wild and no public exploit code.

## Other vulnerabilities in Arm Mbed Tls

- [CVE-2026-34877](https://insights.sbomify.com/CVE-2026-34877/): Deserialization in n/a (critical 9.8)
- [CVE-2022-46393](https://insights.sbomify.com/CVE-2022-46393/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-44732](https://insights.sbomify.com/CVE-2021-44732/): Use after free in n/a (critical 9.8)
- [CVE-2017-18187](https://insights.sbomify.com/CVE-2017-18187/): Integer overflow in n/a (critical 9.8)
- [CVE-2018-0487](https://insights.sbomify.com/CVE-2018-0487/): Memory corruption in ARM mbed TLS before 1.3.22, before 2.1.10, and before 2.7.0 (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-24119 and fix it if it is affected.

What it is: CVE-2021-24119 is a medium-severity vulnerability in Arm Mbed Tls, published on 14 Jul 2021. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-24119 in the wild and no public exploit code.

Affected product: Arm Mbed Tls. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-24119/ (Markdown: https://insights.sbomify.com/CVE-2021-24119/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-24119
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-24119
- OSV: https://osv.dev/vulnerability/CVE-2021-24119

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-24119/
Summaries are generated and may contain mistakes; the official description above is the record.