CVE-2021-35243Network attack vector

Unauthenticated data modification via enabled HTTP methods

Published Dec 23, 2021 · Updated Sep 16, 2024

Exposed HTTP methods in SolarWinds Web Help Desk 12.7.7 and earlier allow remote attackers to modify server resources without authentication. The embedded web server leaves PUT and DELETE enabled, accepting user-chosen resource URLs for uploads and removal instead of restricting these dangerous methods. Network reachability is sufficient to place data at chosen server URLs or remove resource associations, causing integrity loss without reported confidentiality or availability effects.

CVSS severity7.5
High
EPSS probability0.90%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Exposed HTTP methods in SolarWinds Web Help Desk 12.7.7 and earlier allow remote attackers to modify server resources without authentication. The embedded web server leaves PUT and DELETE enabled, accepting user-chosen resource URLs for uploads and removal instead of restricting these dangerous methods. Network reachability is sufficient to place data at chosen server URLs or remove resource associations, causing integrity loss without reported confidentiality or availability effects.

The record

CVE
CVE-2021-35243
Published
Dec 23, 2021
Updated
Sep 16, 2024
Vendor
SolarWinds
Product
Web Help Desk
Classifications
CWE-749, T1565.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 23, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=12.7.7 and previous versions 12.7.7 HF1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SolarWinds · Web Help Deskversion=12.7.7 and previous versions 12.7.7 HF1

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/A:N
5.3SolarWindsCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-749Exposed Dangerous Method or Function
T1565.001Stored Data Manipulation

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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