Assessment
Why it matters
CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 58.5%; technical severity is CVSS 8.8.
Microsoft Silverlight 5 before 5.1.41212.0 mishandles negative offsets during decoding, which allows remote attackers to execute arbitrary code or cause a denial of service (object-header corruption) via a crafted web site, aka "Silverlight Runtime Remote Code Execution Vulnerability."
Who should care
- Teams operating Silverlight
- Vulnerability and exposure management teams
- Security operations teams monitoring exploitation activity
Response plan
What I would do
- Confirm whether Silverlight is present in the environment.
- Identify affected versions and establish whether vulnerable services are exposed or reachable.
- Microsoft Security patch Ms16 006
- Review relevant security telemetry for evidence of attempted or successful exploitation.
- Document the remediation decision and track it to verified completion.
Treatment intelligence
Remediation intelligence
Vendor sources are listed before government and third-party guidance. Confirm product applicability and change prerequisites before deployment.
Verification noteAutomated link verification has not completed for this guidance yet.
Technical details
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- CWE
- CWE-20
- Affected versions
- Microsoft Silverlight (Start Including 5.0, End Excluding 5.1.41212.0)
- Fixed versions
- Microsoft Silverlight (Fixed from 5.1.41212.0)
- Published
- 13 January 2016
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
Signal timeline
- CVE published
- Added to CISA KEV
- Latest EPSS score: 58.5%
- Signal calculated at 82