PT-2023-1044 · Microsoft · Windows L2Tp+1

Ryelv · Published 2023-01-10 · Updated 2025-11-19 · CVE-2023-21543

Positive Technologies (AI Summary)

CVSS v3.1

8.1

High

Base vector

AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Windows Layer 2 Tunneling Protocol (L2TP) (affected versions not specified)

Description The issue is related to a buffer overflow in the implementation of the Layer 2 Tunneling Protocol (L2TP) in Microsoft Windows. It can be exploited by sending a specially crafted connection request to a RAS server, allowing a remote attacker to execute arbitrary code. This can potentially impact the system.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

RCE

Resource Exhaustion

Buffer Overflow

Weakness Enumeration

CWE-400

CWE-119

Related Identifiers

BDU:2023-00138

CVE-2023-21543

Affected Products

Windows

Windows L2Tp

References · 14

• https://nvd.nist.gov/vuln/detail/CVE-2023-21543 · Security Note
• https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2023-21543 · Vendor Advisory
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-21543 · Security Note
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21543 · Vendor Advisory
• https://safe-surf.ru/specialists/bulletins-nkcki/688435 · Security Note
• https://safe-surf.ru/specialists/bulletins-nkcki/688799 · Security Note
• https://bdu.fstec.ru/vul/2023-00138 · Security Note
• https://osv.dev/vulnerability/CVE-2023-21543 · Vendor Advisory
• https://t.me/cvenotify/81298 · Telegram Post
• https://t.me/cibsecurity/56308 · Telegram Post
• https://t.me/cvenotify/41761 · Telegram Post
• https://t.me/cvenotify/41760 · Telegram Post
• https://t.me/cibsecurity/56292 · Telegram Post
• https://t.me/cvenotify/42247 · Telegram Post