Description
A side-channel issue was discovered in Botan before 2.9.0. An attacker capable of precisely measuring the time taken for ECC key generation may be able to derive information about the high bits of the secret key, as the function to derive the public point from the secret scalar uses an unblinded Montgomery ladder whose loop iteration count depends on the bitlength of the secret. This issue affects only key generation, not ECDSA signatures or ECDH key agreement.
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 13 | botan | 2.9.0-2 | — |
| Debian 12 | botan | 2.9.0-2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | botan | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | botan1.10 | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | Botan | 2.18.1-1.3 | openSUSE-SU-2024:10594-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.21 | botan | 2.9.0-r0 | — |
| Alpine v3.20 | botan | 2.9.0-r0 | — |
| Alpine v3.19 | botan | 2.9.0-r0 | — |
| Alpine v3.18 | botan | 2.9.0-r0 | — |
| Alpine v3.17 | botan | 2.9.0-r0 | — |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.16 | botan | 2.9.0-r0 | — |
| Alpine v3.15 | botan | 2.9.0-r0 | — |
| Alpine v3.14 | botan | 2.9.0-r0 | — |
| Alpine v3.13 | botan | 2.9.0-r0 | — |
| Alpine v3.12 | botan | 2.9.0-r0 | — |
| Alpine v3.11 | botan | 2.9.0-r0 | — |
| Alpine v3.10 | botan | 2.9.0-r0 | — |
Advisories 1
- openSUSE-SU-2024:10594-1 Botan-2.18.1-1.3 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026