CVE-2021-35233Network attack vector

Information disclosure via HTTP request reflection

Published Oct 27, 2021 · Updated Sep 16, 2024

HTTP method exposure in SolarWinds Kiwi Syslog Server 9.7.2 and earlier allows remote attackers to read reflected HTTP request data. The bundled Web Access server accepts TRACK and TRACE and returns the exact request, including headers added by intervening reverse proxies. No authentication or user interaction is required; exposure is limited to request data and can reveal internal authentication headers.

CVSS severity5.3
Medium
EPSS probability0.96%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTP method exposure in SolarWinds Kiwi Syslog Server 9.7.2 and earlier allows remote attackers to read reflected HTTP request data. The bundled Web Access server accepts TRACK and TRACE and returns the exact request, including headers added by intervening reverse proxies. No authentication or user interaction is required; exposure is limited to request data and can reveal internal authentication headers.

The record

CVE
CVE-2021-35233
Published
Oct 27, 2021
Updated
Sep 16, 2024
Vendor
SolarWinds
Product
Kiwi Syslog Server
Classifications
CWE-16, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 27, 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=9.7.2 and previous versions <9.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SolarWinds · Kiwi Syslog Serverversion=9.7.2 and previous versions <9.8

Published CVSS scores

5.3SolarWindsCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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-16Configuration
T1190Exploit Public-Facing Application

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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