Description
The ECDSA signature implementation in ecdsa.c in Arm Mbed Crypto 2.1 and Mbed TLS through 2.19.1 does not reduce the blinded scalar before computing the inverse, which allows a local attacker to recover the private key via side-channel attacks.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | mbedtls | 2.16.4-1 | — |
| Debian 13 | mbedtls | 2.16.4-1 | — |
| Debian 12 | mbedtls | 2.16.4-1 | — |
| Debian 10 | mbedtls | 2.16.9-0~deb10u1 | DLA-3249-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | mbedtls | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | mbedtls | No fix yet | — |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | mbedtls +2 | 2.16.4-r0 | — |
| Alpine v3.23 | mbedtls +1 | 2.16.4-r0 | — |
| Alpine v3.22 | mbedtls +1 | 2.16.4-r0 | — |
| Alpine v3.21 | mbedtls +1 | 2.16.4-r0 | — |
| Alpine v3.20 | mbedtls +1 | 2.16.4-r0 | — |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | mbedtls | 2.16.4-r0 | — |
| Alpine v3.18 | mbedtls | 2.16.4-r0 | — |
| Alpine v3.17 | mbedtls | 2.16.4-r0 | — |
| Alpine v3.16 | mbedtls | 2.16.4-r0 | — |
| Alpine v3.15 | mbedtls | 2.16.4-r0 | — |
| Alpine v3.14 | mbedtls | 2.16.4-r0 | — |
| Alpine v3.13 | mbedtls | 2.16.4-r0 | — |
| Alpine v3.12 | mbedtls | 2.16.4-r0 | — |
| Alpine v3.11 | mbedtls | 2.16.4-r0 | — |
| Alpine v3.10 | mbedtls | 2.16.4-r0 | — |
Advisories 2
- DLA-3249-1 mbedtls - security update Debian Security (DSA / DLA) · Mar 9, 2026
- VDE-2021-018 Pepperl+Fuchs: Multiple vulnerabilites in ICE1 Ethernet IO Modules CERT@VDE · May 12, 2021
References
- https://tls.mbed.org/tech-updates/security-advisories
- https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2019-12
- FEDORA-2020-8d3ea0fe8d vendor-advisory
- FEDORA-2020-5bcfae9f46 vendor-advisory
- [debian-lts-announce] 20221225 [SECURITY] [DLA 3249-1] mbedtls security update mailing-list