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CVE-2021-28355: Remote Procedure Call Runtime Remote Code Execution Vulnerability

CVE-2021-28355 is a remote code execution vulnerability in Remote Procedure Call Runtime, rated Important by Microsoft, with a CVSS 3.0 base score of 8.8 (High). An attacker can exploit it remotely over the network, with low privileges and without user interaction. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. The EPSS model estimates a 2.31% probability of exploitation activity in the next 30 days, higher than 83% of all scored vulnerabilities. Microsoft released the fix on 13 April 2021 in the April 2021 Patch Tuesday, delivered through 14 security updates (KB5001339, KB5001342, KB5001337, KB5001330 and more). It affects 41 products in 2 product families (Windows, ESU).

Key facts

CVE ID
CVE-2021-28355
Severity
High CVSS 8.8
Microsoft severity
Important
Impact
Remote Code Execution
Exploited in the wild
No
Publicly disclosed
No
Exploitation likelihood
Less Likely
EPSS
2.31% (percentile 83%)
CISA KEV
Not listed
Released
Last updated
Patch Tuesday
April 2021 Patch Tuesday
Product families
Windows, ESU

CVSS score and vector

Microsoft scores CVE-2021-28355 at 8.8 (temporal 7.7) using CVSS 3.0. Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

MetricValue
Attack vectorNetwork
Attack complexityLow
Privileges requiredLow
User interactionNone
ScopeUnchanged
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
Exploit code maturityUnproven
Remediation levelOfficial fix
Report confidenceConfirmed

NVD scores it 8.8 (HIGH) with CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products (41)

Windows

ProductSecurity updateTypeFixed buildRestart
Windows 10 Version 1803 for 32-bit SystemsKB5001339Security UpdateYes
Windows 10 Version 1803 for x64-based SystemsKB5001339Security UpdateYes
Windows 10 Version 1803 for ARM64-based SystemsKB5001339Security UpdateYes
Windows 10 Version 1809 for 32-bit SystemsKB5001342Security UpdateYes
Windows 10 Version 1809 for x64-based SystemsKB5001342Security UpdateYes
Windows 10 Version 1809 for ARM64-based SystemsKB5001342Security UpdateYes
Windows Server 2019KB5001342Security UpdateYes
Windows Server 2019 (Server Core installation)KB5001342Security UpdateYes
Windows 10 Version 1909 for 32-bit SystemsKB5001337Security UpdateYes
Windows 10 Version 1909 for x64-based SystemsKB5001337Security UpdateYes
Windows 10 Version 1909 for ARM64-based SystemsKB5001337Security UpdateYes
Windows Server, version 1909 (Server Core installation)KB5001337Security UpdateYes
Windows 10 Version 2004 for 32-bit SystemsKB5001330Security UpdateYes
Windows 10 Version 2004 for ARM64-based SystemsKB5001330Security UpdateYes
Windows 10 Version 2004 for x64-based SystemsKB5001330Security UpdateYes
Windows Server, version 2004 (Server Core installation)KB5001330Security UpdateYes
Windows 10 Version 20H2 for x64-based SystemsKB5001330Security UpdateYes
Windows 10 Version 20H2 for 32-bit SystemsKB5001330Security UpdateYes
Windows 10 Version 20H2 for ARM64-based SystemsKB5001330Security UpdateYes
Windows Server, version 20H2 (Server Core Installation)KB5001330Security UpdateYes
Windows 10 for 32-bit SystemsKB5001340Security UpdateYes
Windows 10 for x64-based SystemsKB5001340Security UpdateYes
Windows 10 Version 1607 for 32-bit SystemsKB5001347Security UpdateYes
Windows 10 Version 1607 for x64-based SystemsKB5001347Security UpdateYes
Windows Server 2016KB5001347Security UpdateYes
Windows Server 2016 (Server Core installation)KB5001347Security UpdateYes
Windows 8.1 for 32-bit systemsKB5001382
KB5001393		Monthly Rollup
Security Only
Yes
Yes
Windows 8.1 for x64-based systemsKB5001382
KB5001393		Monthly Rollup
Security Only
Yes
Yes
Windows RT 8.1KB5001382Monthly RollupYes
Windows Server 2012KB5001387
KB5001383		Monthly Rollup
Security Only
Yes
Yes
Windows Server 2012 (Server Core installation)KB5001387
KB5001383		Monthly Rollup
Security Only
Yes
Yes
Windows Server 2012 R2KB5001382
KB5001393		Monthly Rollup
Security Only
Yes
Yes
Windows Server 2012 R2 (Server Core installation)KB5001382
KB5001393		Monthly Rollup
Security Only
Yes
Yes

ESU

ProductSecurity updateTypeFixed buildRestart
Windows 7 for 32-bit Systems Service Pack 1KB5001335
KB5001392		Monthly Rollup
Security Only
Yes
Yes
Windows 7 for x64-based Systems Service Pack 1KB5001335
KB5001392		Monthly Rollup
Security Only
Yes
Yes
Windows Server 2008 for 32-bit Systems Service Pack 2KB5001389
KB5001332		Monthly Rollup
Security Only
Yes
Yes
Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)KB5001389
KB5001332		Monthly Rollup
Security Only
Yes
Yes
Windows Server 2008 for x64-based Systems Service Pack 2KB5001389
KB5001332		Monthly Rollup
Security Only
Yes
Yes
Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)KB5001389
KB5001332		Monthly Rollup
Security Only
Yes
Yes
Windows Server 2008 R2 for x64-based Systems Service Pack 1KB5001335
KB5001392		Monthly Rollup
Security Only
Yes
Yes
Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)KB5001335
KB5001392		Monthly Rollup
Security Only
Yes
Yes

Security updates (14)

NIST NVD data

NVD status
Modified
NVD CVSS
8.8 (HIGH)
Published to NVD
NVD last modified

Affected configurations (CPE)

ProductVulnerable versions
windows 10all listed versions
windows 10 20h2all listed versions
windows 10 1607all listed versions
windows 10 1803all listed versions
windows 10 1809all listed versions
windows 10 1909all listed versions
windows 10 2004all listed versions
windows 7all listed versions
windows 8.1all listed versions
windows rt 8.1all listed versions
windows server 2008all listed versions
windows server 2008 r2 (x64)all listed versions
windows server 2012all listed versions
windows server 2012 r2all listed versions
windows server 2016all listed versions
windows server 2016 20h2all listed versions
windows server 2016 1909all listed versions
windows server 2016 2004all listed versions
windows server 2019all listed versions

References

Acknowledgments

  • Yuki Chen

Revision history

VersionDateDescription
1.0Information published.

Sources