SB2023011048 - Multiple vulnerabilities in Microsoft Windows Layer 2 Tunneling Protocol (L2TP)

Description

This security bulletin contains information about 6 secuirty vulnerabilities.

1) Use-after-free (CVE-ID: CVE-2023-21679)

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

The vulnerability exists due to a boundary error in Windows Layer 2 Tunneling Protocol (L2TP) implementation. A remote attacker can send specially crafted packets to the RAS server, trigger a use-after-free error and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of the vulnerable system.

2) Use-after-free (CVE-ID: CVE-2023-21546)

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

The vulnerability exists due to a boundary error in Windows Layer 2 Tunneling Protocol (L2TP) implementation. A remote attacker can send specially crafted packets to the RAS server, trigger a use-after-free error and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of the vulnerable system.

3) Use-after-free (CVE-ID: CVE-2023-21555)

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

The vulnerability exists due to a boundary error in Windows Layer 2 Tunneling Protocol (L2TP) implementation. A remote attacker can send specially crafted packets to the RAS server, trigger a use-after-free error and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of the vulnerable system.

4) Use-after-free (CVE-ID: CVE-2023-21556)

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

The vulnerability exists due to a boundary error in Windows Layer 2 Tunneling Protocol (L2TP) implementation. A remote attacker can send specially crafted packets to the RAS server, trigger a use-after-free error and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of the vulnerable system.

5) Buffer overflow (CVE-ID: CVE-2023-21543)

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

The vulnerability exists due to a boundary error in Windows Layer 2 Tunneling Protocol (L2TP) implementation. A remote attacker can send specially crafted packets to the RAS server, trigger memory corruption and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

6) Input validation error (CVE-ID: CVE-2023-21757)

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

The vulnerability exists due to insufficient validation of user-supplied input in Windows Layer 2 Tunneling Protocol (L2TP). A remote attacker can send specially crafted packets to the system and perform a denial of service (DoS) attack.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2023-21543
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2023-21757