Assessment
Why it matters
CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 81.9%; technical severity is CVSS 7.8.
Microsoft Silverlight 5, and 5 Developer Runtime, before 5.1.20125.0 does not properly validate pointers during HTML object rendering, which allows remote attackers to execute arbitrary code via a crafted Silverlight application, aka "Silverlight Double Dereference 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.
- The impacted product is end-of-life and should be disconnected if still in use.
- Review relevant security telemetry for evidence of attempted or successful exploitation.
- Document the remediation decision and track it to verified completion.
Vendor remediation
Patch and remediation links
Use the vendor source below to confirm the correct fixed version, package or mitigation for your affected product.
Technical details
- CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- CWE
- Not classified
- Affected versions
- Microsoft Silverlight (Start Including: 5.0, End Excluding: 5.1.20125.0)
- Published
- 12 March 2013
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
Signal timeline
- CVE published
- Added to CISA KEV
- Latest EPSS score: 81.9%
- Signal calculated at 84