Gentoo update for PuTTY



Published: 2024-07-05
Risk Medium
Patch available YES
Number of vulnerabilities 2
CVE-ID CVE-2023-48795
CVE-2024-31497
CWE-ID CWE-326
CWE-310
Exploitation vector Network
Public exploit Public exploit code for vulnerability #2 is available.
Vulnerable software
Subscribe 		Gentoo Linux
Operating systems & Components / Operating system

net-misc/putty
Operating systems & Components / Operating system package or component

Vendor Gentoo

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Inadequate encryption strength

EUVDB-ID: #VU84537

Risk: Low

CVSSv3.1: 3.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-48795

CWE-ID: CWE-326 - Inadequate Encryption Strength

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists due to incorrect implementation of the SSH Binary Packet Protocol (BPP), which mishandles the handshake phase and the use of sequence numbers. A remote attacker can perform MitM attack and delete the SSH2_MSG_EXT_INFO message sent before authentication starts, allowing the attacker to disable a subset of the keystroke timing obfuscation features introduced in OpenSSH 9.5.

The vulnerability was dubbed "Terrapin attack" and it affects both client and server implementations.

Mitigation

Update the affected packages.
net-misc/putty to version: 0.81

Vulnerable software versions

Gentoo Linux: All versions

net-misc/putty: before 0.81

CPE2.3 External links

http://security.gentoo.org/glsa/202407-11


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Cryptographic issues

EUVDB-ID: #VU88542

Risk: Medium

CVSSv3.1: 5.3 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2024-31497

CWE-ID: CWE-310 - Cryptographic Issues

Exploit availability: Yes

Description

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.

Mitigation

Update the affected packages.
net-misc/putty to version: 0.81

Vulnerable software versions

Gentoo Linux: All versions

net-misc/putty: before 0.81

CPE2.3 External links

http://security.gentoo.org/glsa/202407-11


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.



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