#VU17472 Out-of-bounds read in rdesktop - CVE-2018-8796

Vulnerability identifier: #VU17472

Vulnerability risk: Low

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:Clear]

CVE-ID: CVE-2018-8796

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 cause DoS condition on the target system.

The vulnerability exists due to an out-of-bounds read condition in the process_bitmap_updates() function. A remote attacker can trick the victim who is using a Remote Desktop Protocol (RDP) client on a targeted system into connecting to an attacker-controlled RDP server, trigger segmentation fault (segfault) and cause the service to crash.

Mitigation
Update to version 1.8.4.

Vulnerable software versions

rdesktop: 1.0.0 - 1.8.3

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External links
https://github.com/rdesktop/rdesktop/commit/4dca546d04321a610c1835010b5dad85163b65e1

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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.