cbcvebase.
CVE-2018-8288
published 2018-07-11

CVE-2018-8288: A remote code execution vulnerability exists in the way the scripting engine handles objects in memory in Microsoft browsers, aka "Scripting Engine Memory…

PriorityP268high7.5CVSS 3.0
AVNACHPRNUIRSUCHIHAH
EXPLOIT
EPSS
70.03%
99.3th percentile
A remote code execution vulnerability exists in the way the scripting engine handles objects in memory in Microsoft browsers, aka "Scripting Engine Memory Corruption Vulnerability." This affects ChakraCore, Internet Explorer 11, Microsoft Edge. This CVE ID is unique from CVE-2018-8242, CVE-2018-8283, CVE-2018-8287, CVE-2018-8291, CVE-2018-8296, CVE-2018-8298.

Affected

8 ranges
VendorProductVersion rangeFixed in
microsoftchakracore< 1.10.11.10.1
microsoftchakracore
microsoftinternet_explorer
microsoftinternet_explorer
microsoftinternet_explorer
msrcchakracore
msrcinternet_explorer_11
msrcmicrosoft_edge

Detection & IOCsextracted from sources · hover to see the quote

  • The vulnerability is triggered by accessing a property of the uninitialized Intl object, which bypasses ImplicitCallFlags checks in ChakraCore JIT. Monitor for JavaScript patterns that access `Intl` properties to trigger initialization while a hooked `Map.prototype.get` is in place.
  • The PoC exploit pattern involves redefining `Map.prototype.get` to intercept Intl.js execution and corrupt a typed array element (arr[0]) with an object reference, enabling type confusion. Detect JavaScript that overrides Map.prototype.get in conjunction with Intl property access.
  • The exploit uses a JIT warm-up loop of 0x10000 (65536) iterations before triggering the vulnerability. Heuristic detection of tight loops followed by Intl object access and Map.prototype manipulation may indicate exploitation attempts.
  • The magic float constant `2.3023e-320` is used in the PoC to write a near-zero double into a typed array as part of the type confusion primitive. This specific constant in JavaScript source may be a strong indicator of CVE-2018-8288 exploitation.
  • ·The vulnerability affects Microsoft browsers using the ChakraCore scripting engine. Exploitation requires a user to visit a specially crafted website or open a document hosting the browser rendering engine. The exploit is publicly disclosed but was not marked as actively exploited at time of advisory.
  • ·An attacker could also embed an ActiveX control marked 'safe for initialization' in an Office document to trigger the vulnerability outside of a browser context, widening the attack surface beyond web browsing.

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
ghsa7.5HIGH
osv7.5HIGH
vendor_msrc4.2MEDIUM
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