Use-after-free in FreeRDP - CVE-2020-4031

Vulnerability identifier: #VU29360

CSH Severity: High

CVSS v4: 9.3 [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]

CVE-ID: CVE-2020-4031

CWE-ID: CWE-416

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in "gdi_SelectObject" when using compatibility mode with /relax-order-checks. A remote attacker can execute arbitrary code on the target system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

FreeRDP
Arch Linux
Opensuse
Ubuntu
Fedora
freerdp (Alpine package)
libfreerdp-client2-2 (Ubuntu package)
libfreerdp-server2-2 (Ubuntu package)
libfreerdp2-2 (Ubuntu package)
freerdp

Install updates from vendor's website.

FreeRDP - update to 2.1.2
freerdp (Alpine package) - update to 2.1.2-r0
libfreerdp-client2-2 (Ubuntu package) - addressed in versions 2.2.0+dfsg1-0ubuntu0.18.04.1, 2.2.0+dfsg1-0ubuntu0.20.04.1
libfreerdp-server2-2 (Ubuntu package) - addressed in versions 2.2.0+dfsg1-0ubuntu0.18.04.1, 2.2.0+dfsg1-0ubuntu0.20.04.1
libfreerdp2-2 (Ubuntu package) - addressed in versions 2.2.0+dfsg1-0ubuntu0.18.04.1, 2.2.0+dfsg1-0ubuntu0.20.04.1
freerdp - addressed in versions 2.2.0-1.fc31, 2.2.0-1.fc32, 2.2.0-4.fc33

• http://www.freerdp.com/2020/06/22/2_1_2-released
• https://github.com/FreeRDP/FreeRDP/commit/6d86e20e1e7caaab4f0c7f89e36d32914dbccc52
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-gwcq-hpq2-m74g

• Multiple vulnerabilities in FreeRDP
• Arch Linux update for freerdp
• OpenSUSE Linux update for freerdp
• Use-after-free in freerdp (Alpine package)
• Ubuntu update for freerdp2
• Fedora 31 update for freerdp
• Fedora 32 update for freerdp
• Fedora 33 update for freerdp