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NOTICE UPDATED - April, 25th 2024

NIST has updated the NVD program announcement page with additional information regarding recent concerns and the temporary delays in enrichment efforts.

CVE-2024-31497 Detail

Description

In PuTTY 0.68 through 0.80 before 0.81, biased ECDSA nonce generation allows an attacker to recover a user's NIST P-521 secret key via a quick attack in approximately 60 signatures. This is especially important in a scenario where an adversary is able to read messages signed by PuTTY or Pageant. The required set of signed messages may be publicly readable because they are stored in a public Git service that supports use of SSH for commit signing, and the signatures were made by Pageant through an agent-forwarding mechanism. In other words, an adversary may already have enough signature information to compromise a victim's private key, even if there is no further use of vulnerable PuTTY versions. After a key compromise, an adversary may be able to conduct supply-chain attacks on software maintained in Git. A second, independent scenario is that the adversary is an operator of an SSH server to which the victim authenticates (for remote login or file copy), even though this server is not fully trusted by the victim, and the victim uses the same private key for SSH connections to other services operated by other entities. Here, the rogue server operator (who would otherwise have no way to determine the victim's private key) can derive the victim's private key, and then use it for unauthorized access to those other services. If the other services include Git services, then again it may be possible to conduct supply-chain attacks on software maintained in Git. This also affects, for example, FileZilla before 3.67.0, WinSCP before 6.3.3, TortoiseGit before 2.15.0.1, and TortoiseSVN through 1.14.6.


Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  N/A
NVD assessment not yet provided.


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have not published a CVSS score for this CVE at this time. NVD Analysts use publicly available information at the time of analysis to associate CVSS vector strings.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://bugzilla.redhat.com/show_bug.cgi?id=2275183
https://bugzilla.suse.com/show_bug.cgi?id=1222864
https://docs.ccv.brown.edu/oscar/connecting-to-oscar/ssh/ssh-agent-forwarding/key-generation-and-agent-forwarding-with-putty
https://filezilla-project.org/versions.php
https://git.tartarus.org/?h=c193fe9848f50a88a4089aac647fecc31ae96d27&p=simon/putty.git
https://github.com/advisories/GHSA-6p4c-r453-8743
https://github.com/daedalus/BreakingECDSAwithLLL
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZS3B37GNGWOOV7QU7B7JFK76U4TOP4V/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MMHILY2K7HQGQRHOC375KRRG2M6625RD/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PUOTQVGC4DISVHQGSPUYGXO6TLDK65LA/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WFDZBV7ZCAZ6AH3VCQ34SSY7L3J7VZXZ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WMJH7M663BVO3SY6MFAW2FAZWLLXAPRQ/
https://news.ycombinator.com/item?id=40044665
https://security-tracker.debian.org/tracker/CVE-2024-31497
https://securityonline.info/cve-2024-31497-critical-putty-vulnerability-exposes-private-keys-immediate-action-required/
https://tartarus.org/~simon/putty-snapshots/htmldoc/Chapter9.html#pageant-forward
https://tortoisegit.org
https://twitter.com/CCBalert/status/1780229237569470549
https://twitter.com/lambdafu/status/1779969509522133272
https://winscp.net/eng/news.php
https://www.bleepingcomputer.com/news/security/putty-ssh-client-flaw-allows-recovery-of-cryptographic-private-keys/
https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html
https://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-p521-bias.html
https://www.openwall.com/lists/oss-security/2024/04/15/6
https://www.reddit.com/r/sysadmin/comments/1c4wmoj/putty_vulnerability_affecting_v068_to_v08/

Weakness Enumeration

CWE-ID CWE Name Source

Change History

9 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2024-31497
NVD Published Date:
04/15/2024
NVD Last Modified:
04/25/2024
Source:
MITRE