#VU18008 Out-of-bounds read in rdesktop - CVE-2018-20174

Vulnerability identifier: #VU18008

Vulnerability risk: Medium

CVSSv4.0: 5.5 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2018-20174

CWE-ID: CWE-125

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
rdesktop
Server applications / Other server solutions

Vendor: rdesktop.org

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to a boundary error in the function ui_clip_handle_data(). A remote attacker can send a specially crafted request to the affected application, trigger out-of-bounds read error and read contents of memory on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

rdesktop: 1.0.0 - 1.8.3

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External links
https://github.com/rdesktop/rdesktop/commit/4dca546d04321a610c1835010b5dad85163b65e1
https://research.checkpoint.com/reverse-rdp-attack-code-execution-on-rdp-clients/

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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.