Description
The rsa_verify function in PuTTY before 0.63 (1) does not clear sensitive process memory after use and (2) does not free certain structures containing sensitive process memory, which might allow local users to discover private RSA and DSA keys.
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 | filezilla | 3.7.3-1 | — |
| Debian 14 | putty | 0.63-1 | — |
| Debian 13 | filezilla | 3.7.3-1 | — |
| Debian 13 | putty | 0.63-1 | — |
| Debian 12 | filezilla | 3.7.3-1 | — |
| Debian 12 | putty | 0.63-1 | — |
| Debian 7 | putty | 0.62-9+deb7u1 | DSA-2736-1 |
| Debian 6.0 | putty | 0.60+2010-02-20-1+squeeze2 | DSA-2736-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | filezilla | 3.23.0.2-1.1 | openSUSE-SU-2024:10399-1 |
Advisories 2
- DSA-2736-1 putty - several Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10399-1 filezilla-3.23.0.2-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- [oss-security] 20130806 CVE request: three additional flaws fixed in putty 0.63 mailing-list
- 54533 third-party-advisory
- http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/private-key-not-wiped.html
- DSA-2736 vendor-advisory
- openSUSE-SU-2013:1347 vendor-advisory
- 54379 third-party-advisory