CVE-2021-35250Network attack vector

Unauthenticated file disclosure via directory traversal

Published Apr 25, 2022 · Updated Sep 16, 2024

Path traversal in SolarWinds Serv-U 15.3 allows remote attackers to read installation and server files over the network. SolarWinds has not disclosed the request path, code locus, or traversal sequence that fails to constrain attacker-controlled file paths. The attack requires no authentication or user interaction and exposes files readable by the Serv-U service, with no reported data modification or service interruption.

CVSS severity7.5
High
EPSS probability12.80%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in SolarWinds Serv-U 15.3 allows remote attackers to read installation and server files over the network. SolarWinds has not disclosed the request path, code locus, or traversal sequence that fails to constrain attacker-controlled file paths. The attack requires no authentication or user interaction and exposes files readable by the Serv-U service, with no reported data modification or service interruption.

The record

CVE
CVE-2021-35250
Published
Apr 25, 2022
Updated
Sep 16, 2024
Vendor
SolarWinds
Product
Serv-U
Classifications
CWE-22, T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 25, 2022CVE 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=15.3 only <15.3 Hotfix 1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SolarWinds · Serv-Uversion=15.3 only <15.3 Hotfix 1

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
7.5SolarWindsCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1005Data from Local System

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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