cbcvebase.
CVE-2017-8634
published 2017-08-08

CVE-2017-8634: Microsoft Edge in Microsoft Windows 10 1703 allows an attacker to execute arbitrary code in the context of the current user due to the way that Microsoft…

PriorityP269high7.5CVSS 3.0
AVNACHPRNUIRSUCHIHAH
EXPLOIT
EPSS
70.28%
99.3th percentile
Microsoft Edge in Microsoft Windows 10 1703 allows an attacker to execute arbitrary code in the context of the current user due to the way that Microsoft browser JavaScript engines render content when handling objects in memory, aka "Scripting Engine Memory Corruption Vulnerability". This CVE ID is unique from CVE-2017-8635, CVE-2017-8636, CVE-2017-8638, CVE-2017-8639, CVE-2017-8640, CVE-2017-8641, CVE-2017-8645, CVE-2017-8646, CVE-2017-8647, CVE-2017-8655, CVE-2017-8656, CVE-2017-8657, CVE-2017-8670, CVE-2017-8671, CVE-2017-8672, and CVE-2017-8674.

Affected

6 ranges
VendorProductVersion rangeFixed in
microsoftinternet_explorer
microsoftinternet_explorer
microsoftinternet_explorer
microsoft_corporationmicrosoft_scripting_engine
msrcmicrosoft_edge_on_windows_10_version_1703_for_32-bit_systems
msrcmicrosoft_edge_on_windows_10_version_1703_for_x64-based_systems

Detection & IOCsextracted from sources · hover to see the quote

urlhttps://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4034674
  • Look for JavaScript triggering Array.prototype.concat with a getter on Symbol.isConcatSpreadable that mutates array element types mid-execution — this is the type confusion trigger pattern for CVE-2017-8634 in Chakra's JavascriptArray::ConcatArgs.
  • The vulnerability is triggered in Microsoft Edge's Chakra engine via the JavascriptArray::ConcatArgs code path; monitor for Edge renderer crashes or JIT anomalies involving concat operations with isConcatSpreadable side effects.
  • Attacker delivery vector includes specially crafted websites, compromised websites hosting user-provided content or advertisements, and ActiveX controls embedded in Office documents — monitor for Edge navigating to suspicious external pages or Office spawning Edge/scripting engine processes.
  • ·Vulnerability is specific to Microsoft Edge on Windows 10 version 1703 only; older software release exploitation rating is N/A.
  • ·At time of advisory publication, exploit status was 'Publicly Disclosed: No; Exploited: No' but rated 'Exploitation More Likely' for the latest software release — prioritize patching accordingly.

CVSS provenance

nvdv3.07.5HIGHCVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
nvdv2.07.6HIGHAV:N/AC:H/Au:N/C:C/I:C/A:C
vendor_msrc4.2MEDIUM
CVEs like this are exactly what “Exploited This Week” covers.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.