Attacker Value
Unknown
(1 user assessed)
Exploitability
Unknown
(1 user assessed)
User Interaction
Required
Privileges Required
None
Attack Vector
Network
2

CVE-2021-21148

Disclosure Date: February 09, 2021
Exploited in the Wild
Reported by gwillcox-r7
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

Heap buffer overflow in V8 in Google Chrome prior to 88.0.4324.150 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.

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3
Technical Analysis

Reported as exploited in the wild at https://chromereleases.googleblog.com/2021/02/stable-channel-update-for-desktop_4.html. Several news articles such as https://www.theverge.com/2021/2/5/22267872/chrome-88-zero-day-vulnerability-government-backed-hackers-security-researchers have suggested that given the timing of this bug, and that it was reported one day before Google’s report on the North Korea hackers targeting security researchers (see https://www.theverge.com/2021/1/26/22250060/google-threat-analysis-group-north-korean-hackers-cybersecurity-researchers-social-engineering), it may be related to the 0day Chrome bug that was used by North Korean state actors in that engagement.

Given this is a remote heap overflow in the browser there may be some concerns regarding reliability though and whilst I’m sure there will be public exploits for this bug, I do question how reliable they will be given the nature of trying to exploit heap exploits. I would imagine the exploit would take advantage of JavaScript to craft the heap appropriately. Therefore a temporary, but not recommended, precaution may be to disable JavaScript in Chrome until one can apply this update.

Please note that Chrome will automatically apply the update if you open and close your browser. However people do tend to keep Chrome open with many tabs and then suspend their PC at the end of the day, so its possible that these patches will likely see an uptick in application when the next Patch Tuesday or company wide patch cycle is enforced and people are forced to reboot their PCs to apply patches, and therefore restart Chrome.

CVSS V3 Severity and Metrics
Base Score:
8.8 High
Impact Score:
5.9
Exploitability Score:
2.8
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
None
User Interaction (UI):
Required
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Vendors

  • Google

Products

  • Chrome
Technical Analysis