CVE-2024-31497

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

5.72% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 93.0% of scored records. A rank, not a probability.

NVD base score

5.9 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2024-04-15 00:00Z2 YR AGO

Last updated

2025-11-04 22:06Z11 MO AGO

Reserved

2024-04-04

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Medium (CVSS 5.9)

CNA CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Weaknesses

• CWE-338Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)Base

Data version

5.2

Document digest

bc67bfe79027873f7b85bdaa8bcea3fda60d145c4d74704124874255f7eb3b6e

• www.chiark.greenend.org.ukhttps://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html
• filezilla-project.orghttps://filezilla-project.org/versions.php
• www.chiark.greenend.org.ukhttps://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-p521-bias.html
• www.openwall.comhttps://www.openwall.com/lists/oss-security/2024/04/15/6
• tartarus.orghttps://tartarus.org/~simon/putty-snapshots/htmldoc/Chapter9.html#pageant-forward
• docs.ccv.brown.eduhttps://docs.ccv.brown.edu/oscar/connecting-to-oscar/ssh/ssh-agent-forwarding/key-generation-and-agent-forwarding-with-putty
• news.ycombinator.comhttps://news.ycombinator.com/item?id=40044665
• winscp.nethttps://winscp.net/eng/news.php
• tortoisegit.orghttps://tortoisegit.org
• github.comhttps://github.com/advisories/GHSA-6p4c-r453-8743
• bugzilla.redhat.comhttps://bugzilla.redhat.com/show_bug.cgi?id=2275183
• bugzilla.suse.comhttps://bugzilla.suse.com/show_bug.cgi?id=1222864
• security-tracker.debian.orghttps://security-tracker.debian.org/tracker/CVE-2024-31497
• twitter.comhttps://twitter.com/lambdafu/status/1779969509522133272
• git.tartarus.orghttps://git.tartarus.org/?h=c193fe9848f50a88a4089aac647fecc31ae96d27&p=simon/putty.git
• www.reddit.comhttps://www.reddit.com/r/sysadmin/comments/1c4wmoj/putty_vulnerability_affecting_v068_to_v08/
• github.comhttps://github.com/daedalus/BreakingECDSAwithLLL
• www.bleepingcomputer.comhttps://www.bleepingcomputer.com/news/security/putty-ssh-client-flaw-allows-recovery-of-cryptographic-private-keys/
• twitter.comhttps://twitter.com/CCBalert/status/1780229237569470549
• securityonline.infohttps://securityonline.info/cve-2024-31497-critical-putty-vulnerability-exposes-private-keys-immediate-action-required/
• lists.fedoraproject.orgFEDORA-2024-8401d42de6https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WMJH7M663BVO3SY6MFAW2FAZWLLXAPRQ/vendor-advisory
• lists.fedoraproject.orgFEDORA-2024-ff9a2fb31chttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MMHILY2K7HQGQRHOC375KRRG2M6625RD/vendor-advisory
• lists.fedoraproject.orgFEDORA-2024-0489e7ba1ehttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZS3B37GNGWOOV7QU7B7JFK76U4TOP4V/vendor-advisory
• lists.fedoraproject.orgFEDORA-2024-08a4a5ead8https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WFDZBV7ZCAZ6AH3VCQ34SSY7L3J7VZXZ/vendor-advisory
• lists.fedoraproject.orgFEDORA-2024-cba85cc558https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PUOTQVGC4DISVHQGSPUYGXO6TLDK65LA/vendor-advisory
• www.openwall.com[oss-security] 20240415 CVE-2024-31497: Secret Key Recovery of NIST P-521 Private Keys Through Biased ECDSA Nonces in PuTTY Clienthttp://www.openwall.com/lists/oss-security/2024/04/15/6mailing-list
• lists.debian.org[debian-lts-announce] 20240620 [SECURITY] [DLA 3839-1] putty security updatehttps://lists.debian.org/debian-lts-announce/2024/06/msg00014.htmlmailing-list
• www.vicarius.iohttps://www.vicarius.io/vsociety/posts/understanding-a-critical-vulnerability-in-putty-biased-ecdsa-nonce-generation-revealing-nist-p-521-private-keys-cve-2024-31497
• lists.fedoraproject.orghttps://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PUOTQVGC4DISVHQGSPUYGXO6TLDK65LA/
• lists.fedoraproject.orghttps://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IZS3B37GNGWOOV7QU7B7JFK76U4TOP4V/
• lists.fedoraproject.orghttps://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WMJH7M663BVO3SY6MFAW2FAZWLLXAPRQ/
• lists.fedoraproject.orghttps://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MMHILY2K7HQGQRHOC375KRRG2M6625RD/