CVE-2021-35221

Authenticated code execution via ImportAlert configuration tampering

Published Aug 31, 2021 · Updated Aug 4, 2024

Improper access control in SolarWinds Platform through 2020.2.6 HF1 allows remote authenticated users to execute code via ImportAlert. The ImportAlert function accepts a guest-authenticated request from the Alerts Settings page and writes attacker-chosen SMTP server entries into the server configuration. SolarWinds has not disclosed how an added SMTP server produces code execution; reachability requires a guest or higher account on an adjacent network.

CVSS severity6.3
Medium
EPSS probability2.04%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in SolarWinds Platform through 2020.2.6 HF1 allows remote authenticated users to execute code via ImportAlert. The ImportAlert function accepts a guest-authenticated request from the Alerts Settings page and writes attacker-chosen SMTP server entries into the server configuration. SolarWinds has not disclosed how an added SMTP server produces code execution; reachability requires a guest or higher account on an adjacent network.

The record

CVE
CVE-2021-35221
Published
Aug 31, 2021
Updated
Aug 4, 2024
Vendor
SolarWinds
Product
SolarWinds Platform
Classifications
CWE-284, T1210
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 31, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=2020.2.6 and previous versions <=2020.2.6 HF1

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

SolarWinds · SolarWinds Platformversion=2020.2.6 and previous versions <=2020.2.6 HF1

Published CVSS scores

5.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:N
8.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
6.3SolarWindsCVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-284Improper Access Control
T1210Exploitation of Remote Services

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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