Use-after-free in libdxfrw - CVE-2021-21900

Vulnerability identifier: #VU63895

CSH Severity: High

CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2021-21900

CWE-ID: CWE-416

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to execute arbitrary code on the system.

The vulnerability exists due to a use-after-free error in the dxfRW::processLType() function. A remote attacker can trick the victim into opening a specially crafted .dwg file, trigger use-after-free, and execute arbitrary code on the target system.

libdxfrw
Debian Linux
Gentoo Linux
Fedora
Ubuntu
librecad (Ubuntu package)
libdxfrw
media-gfx/librecad
librecad (Debian package)
librecad

Install update from vendor's website.

libdxfrw - update to 1.1.0 rc1
librecad (Ubuntu package) - addressed in versions Ubuntu Pro, 2.1.3-1.2+deb10u1build0.20.04.1
libdxfrw - addressed in versions 1.0.1-1.el7, 1.0.1-1.fc33, 1.0.1-1.fc34, 1.0.1-1.fc35
media-gfx/librecad - update to 2.1.3-r7
librecad (Debian package) - addressed in versions 2.1.3-1.2+deb10u1, 2.1.3-1.3+deb11u1
librecad - addressed in versions 2.2.0-0.11.rc2.el7, 2.2.0-0.11.rc2.fc33, 2.2.0-0.11.rc2.fc34, 2.2.0-0.11.rc2.fc35

• https://talosintelligence.com/vulnerability_reports/TALOS-2021-1351
• https://github.com/LibreCAD/libdxfrw/commit/fcd977cc7f8f6cc7f012e5b72d33cf7d77b3fa69

• Debian update for librecad
• Multiple vulnerabilities in LibreCAD libdxfrw
• Ubuntu update for librecad
• Gentoo update for LibreCAD
• Fedora 35 update for libdxfrw, librecad
• Fedora 33 update for libdxfrw, librecad
• Fedora 34 update for libdxfrw, librecad
• Fedora EPEL 7 update for libdxfrw, librecad