SB2023111454 - Multiple vulnerabilities in Microsoft Exchange Server

Description

This security bulletin contains information about 4 secuirty vulnerabilities.

1) Deserialization of Untrusted Data (CVE-ID: CVE-2023-36050)

The vulnerability allows a remote user to gain access to sensitive information.

The vulnerability exists due to insecure input validation when processing serialized data within the SerializationTypeConverter class in TransportConfigContainer. A remote user can pass specially crafted data to the application and gain access to sensitive information.

2) Information disclosure (CVE-ID: CVE-2023-36035)

The vulnerability allows a remote user to gain access to potentially sensitive information.

The vulnerability exists due to an error within the IsUNCPath method in Microsoft Exchange server. A remote user on the local network can access a user's Net-NTLMv2 hash and perform NTLM Relay attack against another service to authenticate as the user.

3) Deserialization of Untrusted Data (CVE-ID: CVE-2023-36039)

The vulnerability allows a remote user to gain access to sensitive information.

The vulnerability exists due to an error within the SerializationTypeConverter class in FederationTrust. A remote user on the local network can access a user's Net-NTLMv2 hash and perform NTLM Relay attack against another service to authenticate as the user.

4) Deserialization of Untrusted Data (CVE-ID: CVE-2023-36439)

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

The vulnerability exists due to insecure input validation when processing serialized data. A remote user on the local network can pass specially crafted data to the application and execute arbitrary code on the target system.

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

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2023-36050
• https://www.zerodayinitiative.com/advisories/ZDI-23-1640/
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2023-36035
• https://www.zerodayinitiative.com/advisories/ZDI-23-1637/
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2023-36039
• https://www.zerodayinitiative.com/advisories/ZDI-23-1641/
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2023-36439