Input validation error in libssh (Alpine package)

1) Input validation error

EUVDB-ID: #VU33914

Risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2012-4561

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to perform service disruption.

The (1) publickey_make_dss, (2) publickey_make_rsa, (3) signature_from_string, (4) ssh_do_sign, and (5) ssh_sign_session_id functions in keys.c in libssh before 0.5.3 free "an invalid pointer on an error path," which might allow remote attackers to cause a denial of service (crash) via unspecified vectors.

Mitigation

Install update from vendor's website.

Vulnerable software versions

libssh (Alpine package): 0.4.8-r0 - 0.5.2-r1

CPE2.3

• cpe:2.3:a:alpine:libssh_alpine_package:0.4.8-r0:*:*:*:*:alpine_linux:*:2.1
• cpe:2.3:a:alpine:libssh_alpine_package:0.5.2-r1:*:*:*:*:alpine_linux:*:2.3

External links

https://git.alpinelinux.org/aports/commit/?id=3aa8dade2d1f5f2305e19a6b358c2387cad1e44e
https://git.alpinelinux.org/aports/commit/?id=64fa42e2bc50a87954e1da1bc1b7d046a3f8a3e0
https://git.alpinelinux.org/aports/commit/?id=83c66142a67d9bcd991f2e6336e51ec8c190ceb6
https://git.alpinelinux.org/aports/commit/?id=105ad95e86f1c3023bbff961a80bbce2265ef164

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.