Actively exploited vulnerability
Microsoft Office: security bypass flaw under attack
CVE-2023-21715 · Microsoft Office Publisher Security Feature Bypass Vulnerability
What is affected
Microsoft Office is found on ordinary personal computers and phones, so this is not only a problem for companies. If you use it and have not updated since the fix was released, you are exposed.
Microsoft Office Publisher contains a security feature bypass vulnerability that allows for a local, authenticated attack on a targeted system.
What an attacker can do
This is a security bypass flaw. It lets an attacker slip past a built-in protection, so warnings and checks that normally stop malicious content never appear.
- How it is reached
- Needs access to the device or a file opened on it
- Access the attacker needs
- A basic user account
- Does the victim have to do something?
- Yes, the victim must open or click something
What to do
- Update Microsoft Office now. Open the update or "About" screen, install whatever is offered and restart the app or device, because the fix is not active until you do.
- Turn on automatic updates so the next fix arrives without you having to look for it.
- If your device is too old to receive this update, stop using the affected app for anything sensitive and plan a replacement.
Apply updates per vendor instructions.
Vendor advisories and fixes
- msrc.microsoft.commsrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2023-21715
How urgent is it
CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on February 14, 2023, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by March 7, 2023, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.
The EPSS model estimates a 12% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 96% of all scored vulnerabilities.
Its CVSS severity score is 7.3 out of 10 (high), as recorded in the US National Vulnerability Database.
Technical description
Microsoft Publisher Security Feature Bypass Vulnerability