Description
PuTTY before 0.73 might allow remote SSH-1 servers to cause a denial of service by accessing freed memory locations via an SSH1_MSG_DISCONNECT message.
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 | putty | 0.73-1 | — |
| Debian 13 | putty | 0.73-1 | — |
| Debian 12 | putty | 0.73-1 | — |
| Debian 10 | putty | 0.74-1+deb11u1~deb10u1 | DLA-3794-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | putty | No fix yet | — |
| Ubuntu 16.04 LTS | putty | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP1 | putty | 0.73-bp151.4.6.1 | openSUSE-SU-2019:2292-1 |
| SUSE Package Hub 15 | putty | 0.73-bp151.4.6.1 | openSUSE-SU-2019:2292-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | putty | 0.76-1.2 | openSUSE-SU-2024:11201-1 |
| openSUSE Leap 15.1 | putty | 0.73-lp151.3.6.1 | openSUSE-SU-2019:2277-1 |
| openSUSE Leap 15.0 | putty | 0.73-lp150.18.1 | openSUSE-SU-2019:2276-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | putty | 0.73-r0 | — |
| Alpine v3.23 | putty | 0.73-r0 | — |
| Alpine v3.22 | putty | 0.73-r0 | — |
| Alpine v3.21 | putty | 0.73-r0 | — |
| Alpine v3.20 | putty | 0.73-r0 | — |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | putty | 0.73-r0 | — |
| Alpine v3.18 | putty | 0.73-r0 | — |
| Alpine v3.17 | putty | 0.73-r0 | — |
| Alpine v3.16 | putty | 0.73-r0 | — |
| Alpine v3.15 | putty | 0.73-r0 | — |
| Alpine v3.14 | putty | 0.73-r0 | — |
| Alpine v3.13 | putty | 0.73-r0 | — |
| Alpine v3.12 | putty | 0.73-r0 | — |
| Alpine v3.11 | putty | 0.73-r0 | — |
| Alpine v3.10 | putty | 0.73-r0 | — |
| Alpine v3.9 | putty | 0.73-r0 | — |
| Alpine v3.8 | putty | 0.73-r0 | — |
Advisories 6
- DLA-3794-1 putty - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2019:2277-1 Security update for putty SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2019:2276-1 Security update for putty SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11201-1 putty-0.76-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2019:2292-1 Security update for putty SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2024-0976 PuTTY: Mehrere Schwachstellen BSI CERT-Bund (WID) · Apr 25, 2024
References
- https://lists.tartarus.org/pipermail/putty-announce/2019/000029.html
- openSUSE-SU-2019:2277 vendor-advisory
- openSUSE-SU-2019:2276 vendor-advisory
- openSUSE-SU-2019:2292 vendor-advisory
- https://security.netapp.com/advisory/ntap-20191127-0003/
- [debian-lts-announce] 20240425 [SECURITY] [DLA 3794-1] putty security update mailing-list