Integer overflow in libssh2 (Alpine package)

1) Integer overflow

EUVDB-ID: #VU22574

Risk: High

CVSSv3.1: 7.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2019-17498

CWE-ID: CWE-190 - Integer overflow

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack or access sensitive information.

The vulnerability exists due to integer overflow in the "SSH_MSG_DISCONNECT" logic in "packet.c" in a bounds check. A remote attacker can specify an arbitrary (out-of-bounds) offset for a subsequent memory read, trigger out-of-bounds read, disclose sensitive information or cause a denial of service condition on the target system when a user connects to the malicious SSH server.

Mitigation

Install update from vendor's website.

Vulnerable software versions

libssh2 (Alpine package): 1.3.0-r0 - 1.9.0-r1

External links

http://git.alpinelinux.org/aports/commit/?id=d33ef701a0f9572919bab33d45f26a7e53ddb156
http://git.alpinelinux.org/aports/commit/?id=db43cc6825c1432f1f003c621cee428ba844860f
http://git.alpinelinux.org/aports/commit/?id=6c763143a08a56997ee6f88f9329cfc17d6b56b5
http://git.alpinelinux.org/aports/commit/?id=7e5d7dd70d3c19875845f534826625d7071f222d
http://git.alpinelinux.org/aports/commit/?id=abdf2ab6d79a67fd9049354e301836e75be57fce

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.