#VU63895 Use-after-free in libdxfrw - CVE-2021-21900

Vulnerability identifier: #VU63895

Vulnerability risk: High

CVSSv4.0: 6.1 [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/E:U/U:Amber]

CVE-ID: CVE-2021-21900

CWE-ID: CWE-416

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
libdxfrw
Universal components / Libraries / Libraries used by multiple products

Vendor: LibreCad

Description

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.

Mitigation
Install update from vendor's website.

Vulnerable software versions

libdxfrw: 0.5.10 - 1.0.1

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

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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.