CVE-2021-21126: Insufficient policy enforcement in extensions

Reference Links

• https://chromereleases.googleblog.com/2021/01/stable-channel-update-for-desktop_19.html (Advisory)
• https://crbug.com/1108126
• https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-21126

Parent vulnerabilities

(Appears in the following advisories)

• 8963246051762193641

Peer vulnerabilities

(Found alongside the following vulnerabilities)

• CVE-2021-21117
• CVE-2021-21118
• CVE-2021-21119
• CVE-2021-21120
• CVE-2021-21121
• CVE-2021-21122
• CVE-2021-21123
• CVE-2021-21124
• CVE-2021-21125
• CVE-2020-16044
• CVE-2021-21127
• CVE-2021-21128
• CVE-2021-21129
• CVE-2021-21130
• CVE-2021-21131
• CVE-2021-21132
• CVE-2021-21133
• CVE-2021-21134
• CVE-2021-21135
• CVE-2021-21136
• CVE-2021-21137
• CVE-2021-21138
• CVE-2021-21139
• CVE-2021-21140
• CVE-2021-21141

Frequently Asked Questions

• What is the vulnerability ID of this security issue?

  The vulnerability ID of this security issue is CVE-2021-21126.

• What is the severity of CVE-2021-21126?

  The severity of CVE-2021-21126 is medium (6.5).

• Which software versions are affected by CVE-2021-21126?

  Google Chrome versions prior to 88.0.4324.96 and Microsoft Edge Chromium versions prior to 88.0.705.50 are affected by CVE-2021-21126.

• What is the impact of CVE-2021-21126?

  CVE-2021-21126 allows a remote attacker to bypass site isolation through a crafted Chrome Extension.

• How can I fix CVE-2021-21126?

  Update Google Chrome to version 88.0.4324.96 or later, and update Microsoft Edge Chromium to version 88.0.705.50 or later to fix CVE-2021-21126.