Microsoft Edge/ChakraCore Scripting Engine out-of-bounds write

Summaryinfo

A vulnerability described as critical has been identified in Microsoft Edge and ChakraCore. This affects an unknown part of the component Scripting Engine. Such manipulation leads to out-of-bounds write. This vulnerability is traded as CVE-2020-1172. The attack may be launched remotely. There is no exploit available. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability was found in Microsoft Edge and ChakraCore (Web Browser) (unknown version) and classified as critical. Affected by this issue is an unknown code block of the component Scripting Engine. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

<p>A remote code execution vulnerability exists in the way that the ChakraCore scripting engine handles objects in memory. The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user.</p> <p>If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.</p> <p>The security update addresses the vulnerability by modifying how the ChakraCore scripting engine handles objects in memory.</p>

The weakness was shared 09/08/2020 as confirmed security update guide (Website). The advisory is shared for download at portal.msrc.microsoft.com. The vendor cooperated in the coordination of the public release. This vulnerability is handled as CVE-2020-1172. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 02/24/2026). The advisory points out:

A remote code execution vulnerability exists in the way that the ChakraCore scripting engine handles objects in memory. The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The entry VDB-160842 is related to this item. Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Web Browser

Vendor

• Microsoft

Name

• ChakraCore
• Edge

License

• commercial

Website

• Vendor: https://www.microsoft.com/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Once again VulDB remains the best source for vulnerability data.

Discussion