CVE-2021-25276Public exploit

LocalSystem file access via writable profile directory

Published Feb 3, 2021 · Updated Aug 3, 2024

Local privilege escalation in SolarWinds Serv-U before 15.2.2 Hotfix 1 allows local users to read or replace arbitrary files. The Windows Users directory grants unprivileged users read and write access to profile files, allowing a valid profile to be copied in as a new FTP account. Filesystem access is required; setting the account home to C:\ exposes files through a service running with LocalSystem privileges.

CVSS severity8.8
High
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Local privilege escalation in SolarWinds Serv-U before 15.2.2 Hotfix 1 allows local users to read or replace arbitrary files. The Windows Users directory grants unprivileged users read and write access to profile files, allowing a valid profile to be copied in as a new FTP account. Filesystem access is required; setting the account home to C:\ exposes files through a service running with LocalSystem privileges.

The record

CVE
CVE-2021-25276
Published
Feb 3, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-732, T1136
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 3, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8SolarWindsCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
3.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-732Incorrect Permission Assignment for Critical Resource
T1136Create Account

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo