#VU34008 NULL pointer dereference in libssh - CVE-2020-16135

Vulnerability identifier: #VU34008

Vulnerability risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2020-16135

CWE-ID: CWE-476

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
libssh
Universal components / Libraries / Libraries used by multiple products

Vendor: libssh

Description

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

The vulnerability exists due to a NULL pointer dereference error in tftpserver.c if ssh_buffer_new returns NULL. A remote attacker can perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

libssh: 0.9.4

---

External links
https://bugs.libssh.org/rLIBSSHe631ebb3e2247dd25e9678e6827c20dc73b73238
https://bugs.libssh.org/T232
https://gitlab.com/libssh/libssh-mirror/-/merge_requests/120
https://lists.debian.org/debian-lts-announce/2020/07/msg00034.html

---

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.