Jul 2021: Microsoft Exchange Server Remote Code Execution Vulnerability
CVE-2021-34473 Published on July 14, 2021
Microsoft Exchange Server Remote Code Execution Vulnerability
Microsoft Exchange Server Remote Code Execution Vulnerability
Known Exploited Vulnerability
This Microsoft Exchange Server Remote Code Execution Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. Microsoft Exchange Server Remote Code Execution Vulnerability. This CVE ID is unique from CVE-2021-31196, CVE-2021-31206.
The following remediation steps are recommended / required by November 17, 2021: Apply updates per vendor instructions.
Weakness Type
What is a SSRF Vulnerability?
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.
CVE-2021-34473 has been classified to as a SSRF vulnerability or weakness.
Products Associated with CVE-2021-34473
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Affected Versions
Microsoft Exchange Server 2013 Cumulative Update 23:- Version 15.00.0 and below 15.00.1497.015 is affected.
- Version 15.02.0 and below 15.02.0858.010 is affected.
- Version 15.01.0 and below 15.01.2242.008 is affected.
- Version 15.01.0 and below 15.01.2176.012 is affected.
- Version 15.02.0 and below 15.02.0792.013 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.