CVE-2023-32320Network attack vector

Credential compromise via concurrent rate-limit bypass

Published Jun 22, 2023 · Updated Dec 5, 2024

Brute-force protection bypass in Nextcloud Server allows remote attackers to exceed configured failed-request limits through parallel requests. BruteForceMiddleware::afterController delayed responses before registering failed attempts and did not abort at the maximum delay, so concurrent requests checked the same stale counter. No authentication or user interaction is required; the bypass increases guesses accepted per rate-limit window and exposes protected details if a guess succeeds.

CVSS severity7.5
High
EPSS probability0.87%
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

Brute-force protection bypass in Nextcloud Server allows remote attackers to exceed configured failed-request limits through parallel requests. BruteForceMiddleware::afterController delayed responses before registering failed attempts and did not abort at the maximum delay, so concurrent requests checked the same stale counter. No authentication or user interaction is required; the bypass increases guesses accepted per rate-limit window and exposes protected details if a guess succeeds.

The record

CVE
CVE-2023-32320
Published
Jun 22, 2023
Updated
Dec 5, 2024
Vendor
Nextcloud GmbH
Product
Security Advisories
Classifications
CWE-307, T1110
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 22, 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 Security AdvisoryCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
7.5NIST NVDCVSS: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-307Improper Restriction of Excessive Authentication Attempts
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