#VU18011 Out-of-bounds read in rdesktop - CVE-2018-20176

Vulnerability identifier: #VU18011

Vulnerability risk: Medium

CVSSv4.0: 4.6 [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:U/U:Green]

CVE-ID: CVE-2018-20176

CWE-ID: CWE-125

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
rdesktop
Server applications / Other server solutions

Vendor: rdesktop.org

Description

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

The vulnerability exists due to a boundary condition when processing RDP packets in sec_parse_crypt_info() and sec_recv() functionsin secure.cfile. A remote attacker can trick the victim that is using the vulnerable RDP client to connect to malicious RDP server, trigger out-of-bounds read error and perform denial of service attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

rdesktop: 1.0.0 - 1.8.3

---

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

---

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.