CVE-2023-35172Network attack vector

Account takeover via unthrottled reset-token guesses

Published Jun 23, 2023 · Updated Dec 5, 2024

Improper brute-force protection in Nextcloud Server and Enterprise Server allows remote attackers to guess password-reset links. The public LostController::setPassword endpoint validated attacker-supplied reset tokens without applying the brute-force protection used by the reset form, so repeated guesses were not throttled. No authentication or user interaction is required, but a valid user identifier and a guessed reset token are needed to replace that account's password.

CVSS severity8.7
High
EPSS probability0.92%
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

Improper brute-force protection in Nextcloud Server and Enterprise Server allows remote attackers to guess password-reset links. The public LostController::setPassword endpoint validated attacker-supplied reset tokens without applying the brute-force protection used by the reset form, so repeated guesses were not throttled. No authentication or user interaction is required, but a valid user identifier and a guessed reset token are needed to replace that account's password.

The record

CVE
CVE-2023-35172
Published
Jun 23, 2023
Updated
Dec 5, 2024
Vendor
Nextcloud GmbH
Product
Security Advisories
Classifications
CWE-307, CAPEC-49, T1110
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 23, 2023CVE publishedPublication date reported by the CVE source.
  2. Dec 5, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Nextcloud Enterprise Server >= 21.0.0, < 21.0.9.12
  2. Affected versionversion=Nextcloud Enterprise Server >= 22.0.0, < 22.2.10.12
  3. Affected versionversion=Nextcloud Enterprise Server >= 23.0.0, < 23.0.12.7
  4. Affected versionversion=Nextcloud Enterprise Server >= 24.0.0, < 24.0.12.2
  5. Affected versionversion=Nextcloud Enterprise Server >= 25.0.0, < 25.0.7
  6. Affected versionversion=Nextcloud Enterprise Server >= 26.0.0, < 26.0.2
  7. Affected versionversion=Nextcloud Server >= 25.0.0, < 25.0.7
  8. Affected versionversion=Nextcloud Server >= 26.0.0, < 26.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Nextcloud GmbH · Security Advisoriesversion=Nextcloud Enterprise Server >= 21.0.0, < 21.0.9.12; version=Nextcloud Enterprise Server >= 22.0.0, < 22.2.10.12; version=Nextcloud Enterprise Server >= 23.0.0, < 23.0.12.7; version=Nextcloud Enterprise Server >= 24.0.0, < 24.0.12.2; version=Nextcloud Enterprise Server >= 25.0.0, < 25.0.7; version=Nextcloud Enterprise Server >= 26.0.0, < 26.0.2; version=Nextcloud Server >= 25.0.0, < 25.0.7; version=Nextcloud Server >= 26.0.0, < 26.0.2

Published CVSS scores

8.7GitHub CNACVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/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-307Improper Restriction of Excessive Authentication Attempts
CAPEC-49Password Brute Forcing
T1110Brute Force

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

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