CVE-2021-27277

SYSTEM code execution via unsafe WCF deserialization

Published Apr 22, 2021 · Updated Aug 3, 2024

Deserialization in SolarWinds Orion Virtual Infrastructure Monitor 2020.2 allows local users to execute code as SYSTEM. The OneTimeJobSchedulerEventsService WCF service fails to validate user-supplied serialized data before deserializing it. Exploitation requires the ability to run low-privileged code locally and results in arbitrary code execution with SYSTEM privileges.

CVSS severity7.8
High
EPSS probability1.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization in SolarWinds Orion Virtual Infrastructure Monitor 2020.2 allows local users to execute code as SYSTEM. The OneTimeJobSchedulerEventsService WCF service fails to validate user-supplied serialized data before deserializing it. Exploitation requires the ability to run low-privileged code locally and results in arbitrary code execution with SYSTEM privileges.

The record

CVE
CVE-2021-27277
Published
Apr 22, 2021
Updated
Aug 3, 2024
Vendor
SolarWinds
Product
Orion Virtual Infrastructure Monitor
Classifications
CWE-502, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2020.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

SolarWinds · Orion Virtual Infrastructure Monitorversion=2020.2

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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