FreeBSD : PuTTY and embedders (f.i., filezilla) -- biased RNG with NIST P521/ecdsa-sha2-nistp521 signatures permits recovering private key (080936ba-fbb7-11ee-abc8-6960f2492b1d)

medium Nessus Plugin ID 193367

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Synopsis

The remote FreeBSD host is missing one or more security-related updates.

Description

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the 080936ba-fbb7-11ee-abc8-6960f2492b1d advisory.

- 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. (CVE-2024-31497)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

See Also

https://filezilla-project.org/versions.php

http://www.nessus.org/u?5b14fd0a

https://lists.tartarus.org/pipermail/putty-announce/2024/000038.html

https://nvd.nist.gov/vuln/detail/CVE-2024-31497

http://www.nessus.org/u?5e57529e

http://www.nessus.org/u?efd844aa

Plugin Details

Severity: Medium

ID: 193367

File Name: freebsd_pkg_080936bafbb711eeabc86960f2492b1d.nasl

Version: 1.2

Type: local

Published: 4/16/2024

Updated: 5/13/2024

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.1

CVSS v2

Risk Factor: Medium

Base Score: 5.4

Temporal Score: 4.2

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:N/A:N

CVSS Score Source: CVE-2024-31497

CVSS v3

Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.3

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:freebsd:freebsd, p-cpe:/a:freebsd:freebsd:putty-nogtk, p-cpe:/a:freebsd:freebsd:filezilla, p-cpe:/a:freebsd:freebsd:putty

Required KB Items: Host/local_checks_enabled, Host/FreeBSD/release, Host/FreeBSD/pkg_info

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 4/16/2024

Vulnerability Publication Date: 4/15/2024

Reference Information

CVE: CVE-2024-31497

IAVA: 2024-A-0243