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Sid 1-48360

Message

BROWSER-IE Microsoft Edge JIT floating point value type confusion attempt

Summary

This event is generated when an html file containing malicious values traverses the corporate network.

Impact

Attempted Administrator Privilege Gain

CVE-2018-8555:

CVSS base score 7.5

CVSS impact score 5.9

CVSS exploitability score 1.6

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Detailed information

A type confusion vulnerability has been identified in Windows Edge, that could allow an attacker to execute arbitrary code on the targeted host. The bug specifically occurs in the way the JIT(Just-In-Time) engine for Edge browser handles float values. In certain specific conditions , the dynamically generated JIT code fails to keep track of the type of an object when handling type conversions resulting from assigning float values to this object. This is a type confusion in chakra engine due to insufficient check when setting a float value to var array. CVE-2018-8555: A remote code execution vulnerability exists in the way that the Chakra scripting engine handles objects in memory in Microsoft Edge, aka "Chakra Scripting Engine Memory Corruption Vulnerability." This affects Microsoft Edge, ChakraCore. This CVE ID is unique from CVE-2018-8541, CVE-2018-8542, CVE-2018-8543, CVE-2018-8551, CVE-2018-8556, CVE-2018-8557, CVE-2018-8588.

Affected systems

  • microsoft chakracore -
  • microsoft edge -

Ease of attack

CVE-2018-8555:

Access Vector

Access Complexity

Authentication

False positives

None known

False negatives

None known

Corrective action

Contributors

  • Cisco's Talos Intelligence Group

Additional References

  • portal.msrc.microsoft.com/en-us/security-guidance/advisory/CVE-2018-8555