CVE-2021-31196 Microsoft Exchange Server: information leak
In plain words: The program reveals information it should keep private. Leaked secrets — tokens, passwords or memory contents — that help a bigger attack.
Confirmed exploited by CISA on · US federal patch deadline Sep 11, 2024
What to do
- Install Microsoft's security update for Exchange Server. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- Microsoft Exchange Server Information Disclosure Vulnerability
- Product
- Microsoft Exchange Server
- CISA description
- Microsoft Exchange Server contains an information disclosure vulnerability that allows for remote code execution.
- Type of flaw
- Information leak
- Confirmed exploited
- Aug 21, 2024
- US federal patch deadline
- Sep 11, 2024
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Answering about CVE-2021-31196 ·
Questions about CVE-2021-31196
Is CVE-2021-31196 being exploited?
Yes. CISA added CVE-2021-31196 to its Known Exploited Vulnerabilities catalog on Aug 21, 2024, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2021-31196?
Install Microsoft's security update for Exchange Server. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2021-31196?
Only if you use Microsoft Exchange Server. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.