Heap-based buffer underflow in the modmul function in sshbn.c in PuTTY before 0.63 allows remote SSH servers to cause a denial of service (crash) and possibly trigger memory corruption or code execution via a crafted DSA signature, which is not properly handled when performing certain bit-shifting operations during modular multiplication.
CVSS Details
- CVSS 3.1 Base Score: 6.3
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | Upgrade filezillaUpgrade putty | Jul 30, 2024 | Aug 19, 2013 |
| Freebsd | — | Upgrade putty | Dec 10, 2025 | Aug 7, 2013 |
| Gentoo Linux | — | Upgrade net-ftp/filezilla. | Oct 30, 2017 | Aug 19, 2013 |
| Suse | — | Upgrade filezillaUpgrade filezilla-lang | Dec 12, 2013 | Aug 19, 2013 |
| Ubuntu | — | Upgrade putty | Nov 19, 2024 | Aug 19, 2013 |
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