#VU33453 Integer underflow in Debian Linux - CVE-2018-20180

Vulnerability identifier: #VU33453

Vulnerability risk: High

CVSSv4.0: 8.9 [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:P/U:Amber]

CVE-ID: CVE-2018-20180

CWE-ID: CWE-191

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
Debian Linux
Operating systems & Components / Operating system

Vendor: Debian

Description

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

rdesktop versions up to and including v1.8.3 contain an Integer Underflow that leads to a Heap-Based Buffer Overflow in the function rdpsnddbg_process() and results in memory corruption and probably even a remote code execution.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Debian Linux: 8.0 - 9.0

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External links
https://lists.opensuse.org/opensuse-security-announce/2019-09/msg00040.html
https://www.securityfocus.com/bid/106938
https://github.com/rdesktop/rdesktop/commit/4dca546d04321a610c1835010b5dad85163b65e1
https://lists.debian.org/debian-lts-announce/2019/02/msg00030.html
https://research.checkpoint.com/reverse-rdp-attack-code-execution-on-rdp-clients/
https://security.gentoo.org/glsa/201903-06
https://www.debian.org/security/2019/dsa-4394

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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.