In September 2022, Microsoft patched an information disclosure vulnerability in SPNEGO NEGOEX (CVE-2022-37958). On December 13, Microsoft reclassified the vulnerability as “Critical” severity after IBM Protection X-Drive Purple Security Researcher Valentina Palmiotti found out the vulnerability could allow attackers to remotely execute code.
The vulnerability is in the SPNEGO Extended Negotiation (NEGOEX) Security Mechanism, which enables a consumer and server to negotiate the choice of protection mechanism to use. This vulnerability is a pre-authentication remote code execution vulnerability impacting a huge vary of protocols. It has the probable to be wormable.
The vulnerability could make it possible for attackers to remotely execute arbitrary code by accessing the NEGOEX protocol by way of any Windows application protocol that authenticates, this sort of as Server Message Block (SMB) or Distant Desktop Protocol (RDP), by default. This list of affected protocols is not total and may possibly exist anywhere SPNEGO is in use, which include in Easy Concept Transport Protocol (SMTP) and Hyper Text Transfer Protocol (HTTP) when SPNEGO authentication negotiation is enabled, this sort of as for use with Kerberos or Internet-NTLM authentication.
As opposed to the vulnerability (CVE-2017-0144) exploited by EternalBlue and utilized in the WannaCry ransomware assaults, which only affected the SMB protocol, this vulnerability has a broader scope and could perhaps influence a wider selection of Windows methods because of to a larger attack surface of products and services exposed to the general public world-wide-web (HTTP, RDP, SMB) or on inner networks. This vulnerability does not need person interaction or authentication by a sufferer on a focus on technique.
Microsoft has classed this vulnerability as “Critical,” with all categories rated at a greatest severity with the exception of “Exploit Complexity,” which is rated Substantial, as it may perhaps have to have multiple attempts for productive exploitation. This brings the all round CVSS 3.1 rating to “8.1.” Unpatched methods with the default configuration are vulnerable.
As element of its responsible disclosure plan, X-Pressure Red has labored with Microsoft on this reclassification. In buy to give defenders time to apply the patches, IBM will refrain from releasing full technological particulars till Q2 2023.
Tips
Due to the common use of SPNEGO, we strongly advise that buyers and directors implement the patch straight away to shield versus all prospective attack vectors. The correct is integrated in September 2022 safety updates and impacts all units Home windows 7 and newer.
Extra suggestions from X-Drive Pink incorporate:
- Evaluate what products and services, these kinds of as SMB and RDP, are exposed to the internet.
- Constant monitoring of your assault area, which include Microsoft IIS HTTP world wide web servers that have Home windows Authentication enabled.
- Limit Home windows authentication companies to Kerberos or Internet-NTLM and remove “Negotiate” as a default supplier if the patch are not able to be used.
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