Description
A Bleichenbacher type side-channel based padding oracle attack was found in the way gnutls handles verification of RSA decrypted PKCS#1 v1.5 data. An attacker who is able to run process on the same physical core as the victim process, could use this to extract plaintext or in some cases downgrade any TLS connections to a vulnerable server.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| [UNKNOWN] | gnutls | — | — |
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 | gnutls28 | 3.6.5-2 | — |
| Debian 13 | gnutls28 | 3.6.5-2 | — |
| Debian 12 | gnutls28 | 3.6.5-2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | gnutls28 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | gnutls28 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | gnutls26 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP1 | gnutls | 3.6.7-6.11.1 | SUSE-SU-2019:1351-2 |
| SLES 15 | gnutls | 3.6.7-6.8.1 | SUSE-SU-2019:1351-1, SUSE-SU-2019:1121-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.1 | gnutls | 3.6.7-lp151.2.3.1 | openSUSE-SU-2019:1477-1 |
| openSUSE Leap 15.0 | gnutls | 3.6.7-lp150.9.1 | openSUSE-SU-2019:1477-1, openSUSE-SU-2019:1353-1 |
Advisories 5
- SUSE-SU-2019:1121-1 Security update for gnutls SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2019:1353-1 Security update for gnutls SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:1351-2 Security update for gnutls SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:1351-1 Security update for gnutls SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2019:1477-1 Security update for gnutls SUSE / openSUSE Security Updates · May 7, 2025
References
- 106080 vdb-entry
- openSUSE-SU-2019:1353 vendor-advisory
- openSUSE-SU-2019:1477 vendor-advisory
- http://cat.eyalro.net/
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16868