CVE-2021-4321: Policy bypass in Blink

Reference Links

• https://chromereleases.googleblog.com/2021/05/stable-channel-update-for-desktop_25.html (Advisory)
• https://crbug.com/1161891
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PQKT7EGDD2P3L7S3NXEDDRCPK4NNZNWJ/

Parent vulnerabilities

(Appears in the following advisories)

• 7170632646642454608

Peer vulnerabilities

(Found alongside the following vulnerabilities)

• CVE-2021-30521
• CVE-2021-30522
• CVE-2021-30523
• CVE-2021-30524
• CVE-2021-30525
• CVE-2021-30526
• CVE-2021-30527
• CVE-2021-30528
• CVE-2021-4322
• CVE-2021-30529
• CVE-2021-30530
• CVE-2021-30531
• CVE-2021-30532
• CVE-2021-30533
• CVE-2021-30534
• CVE-2021-30535
• CVE-2021-30542
• CVE-2021-30543
• CVE-2021-30558
• CVE-2021-30536
• CVE-2021-30537
• CVE-2021-30538
• CVE-2021-30539
• CVE-2021-30540

Frequently Asked Questions

• What is the vulnerability ID of this policy bypass in Blink in Google Chrome?

  The vulnerability ID is CVE-2021-4321.

• What is the severity of CVE-2021-4321?

  The severity of CVE-2021-4321 is Medium (4.3).

• How does this vulnerability in Blink in Google Chrome allow a policy bypass?

  This vulnerability allows a remote attacker to bypass content security policy via a crafted HTML page.

• Which versions of Google Chrome are affected by CVE-2021-4321?

  Google Chrome versions prior to 91.0.4472.77 are affected.

• How can I fix CVE-2021-4321?

  To fix CVE-2021-4321, update your Google Chrome browser to version 91.0.4472.77 or later.