Main Vulnerability Database Vulnerabilities #VU88542

Cryptographic issues in PuTTY - CVE-2024-31497

Published: April 15, 2024 / Updated: May 13, 2024

Vulnerability identifier: #VU88542

CSH Severity: Medium

CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2024-31497

CWE-ID: CWE-310

Exploitation vector: Remote access

Exploit availability: Public exploit is available

Vulnerability details

The vulnerability allows a remote attacker to recover NIST P-521 private keys.

The vulnerability exists due to the PuTTY client and all related components generate heavily biased ECDSA nonces in the case of NIST P-521. A remote attacker can recover the NIST P-521 private key using roughly 60 valid ECDSA signatures generated by any PuTTY component under the same key.

Note, if the key has been used to sign arbitrary data (e.g., git commits by forwarding Pageant to a development host), the publicly available signatures (e.g., on GitHub) can be used as well.

Affected software

PuTTY
Gentoo Linux
Fedora
FileZilla
WinSCP
libfilezilla
net-misc/putty
putty
filezilla

How to mitigate CVE-2024-31497

Install updates from vendor's website.

PuTTY - update to 0.81
FileZilla - update to 3.67.0
WinSCP - update to 6.3.3
libfilezilla - addressed in versions 0.47.0-1.fc38, 0.47.0-1.fc39, 0.47.0-1.fc40
net-misc/putty - update to 0.81
putty - addressed in versions 0.81-1.el8, 0.81-1.el9, 0.81-1.fc38, 0.81-1.fc39, 0.81-1.fc40
filezilla - addressed in versions 3.67.0-1.fc38, 3.67.0-1.fc39, 3.67.0-1.fc40

Links to Public Exploits and PoC-codes

External References

https://seclists.org/oss-sec/2024/q2/122