CVE-2021-34473 Microsoft Exchange Server Remote Code Execution
Attackers can exploit a Server-Side Request Forg flaw in Microsoft Exchange Server to achieve remote code execution.
- Exploited in the wild
- Since 3 Nov 2021
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-34473?
CVE-2021-34473 is a critical server-side request forgery vulnerability in Microsoft Exchange Server, published on 14 Jul 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Microsoft Exchange Server Remote Code Execution Vulnerability
Weakness: CWE-918
Which versions are affected by CVE-2021-34473?
It affects 1 product.
Products include Microsoft Exchange Server.
How do I fix CVE-2021-34473?
No fix has been published for CVE-2021-34473 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 17 Nov 2021.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2021-34473 being exploited?
Yes. Attackers have exploited CVE-2021-34473 in the wild since at least 3 Nov 2021, including in ransomware campaigns.
Public exploit code: 1 Metasploit module, 1 Nuclei template and 9 proofs of concept on GitHub.
Other vulnerabilities in Microsoft Exchange Server
- CVE-2024-21410 Microsoft Exchange Server Privilege Escalation
- CVE-2021-26855 Microsoft Exchange Server Remote Code Execution
- CVE-2021-34523 Microsoft Exchange Server Privilege Escalation
- CVE-2023-21529 Microsoft Exchange Server Deserialization of Untrusted Data
- CVE-2022-41080 Microsoft Exchange Server Privilege Escalation
Sources
Also known as GHSA-fgq9-p33g-xcfc.