VDB
CVE-2021-33500
CVE-2021-33500
PUBLISHED
CVSS 7.5 HIGH
PuTTY before 0.75 on Windows allows remote servers to cause a denial of service (Windows GUI hang) by telling the PuTTY window to change its title repeatedly at high speed, which results in many SetWindowTextA or SetWindowTextW calls. NOTE: the same attack methodology may affect some OS-level GUIs on Linux or other platforms for similar reasons.
EPSS 1.91% · 79.1th percentile
Risk Scores
CVSS 3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score
1.91%
79.1th percentile
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Ubuntu:25.10 | putty | 0.83-2, 0, 0.83-3 |
| Ubuntu:18.04:LTS | putty | 0.70-4, 0.70-2, 0.70-1 |
| Ubuntu:24.04:LTS | putty | 0, 0.78-3, 0.80-1build2 |
| Ubuntu:20.04:LTS | putty | 0, 0.73-1, 0.73-2 |
| Ubuntu:22.04:LTS | putty | 0, 0.76-1, 0.75-3 |
| Ubuntu:16.04:LTS | putty | 0.65-2, 0.66-3, 0 |
Timeline
- May 21, 2021 CVE Published
- May 22, 2021 EPSS Score
- May 28, 2021 EPSS Score
- Jul 25, 2021 EPSS Score
- Nov 26, 2021 EPSS Score
- Jan 6, 2022 EPSS Score
- Jan 26, 2022 EPSS Score
- Feb 4, 2022 EPSS Score
- Mar 29, 2022 EPSS Score
- May 30, 2022 EPSS Score
- Aug 1, 2022 EPSS Score
- Oct 2, 2022 EPSS Score
References
- https://ubuntu.com/security/CVE-2021-33500 advisory
- https://docs.ssh-mitm.at/puttydos.html third-party-advisory
- https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html third-party-advisory
- https://www.cve.org/CVERecord?id=CVE-2021-33500 third-party-advisory
- https://github.com/ssh-mitm/ssh-mitm-plugins/blob/main/ssh_mitm_plugins/ssh/putty_dos.py exploit