NVD / CVE Program· CNA GitHub_M

CVE-2023-25816: nextcloud vulnerable to Uncontrolled Resource Consumption

Noroxi assessment

Priority: Monitor (action score 26/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 1.3% (FIRST EPSS); higher than 71.9% of all records.
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: nextcloud security-advisories 25.0.3.
Severity is disputed: the assigning authority (CNA) scores it 4.3, NVD 6.5.

Low priority for now. Upgrade to nextcloud security-advisories 25.0.3 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Nextcloud is an Open Source private cloud software. Versions 25.0.0 and above, prior to 25.0.3, are subject to Uncontrolled Resource Consumption. A user can configure a very long password, consuming more resources on password validation than desired. This issue is patched in 25.0.3 No workaround is available.

MediumCVSS 6.5 · v3.1—No exploit Fix available

Denial of service

BDU:2023-02153

Published: Feb 24, 2023
Updated: Jun 17, 2026
EPSS: 1.3% · 71th percentile
CWE: CWE-400

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 26 / 40 · 6.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 1.3%

CISA SSVC decision

Exploitation: proof of concept
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 6.5
CNA · GitHub_M: 4.3; 2.2 point gap

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
nextcloud	nextcloud server	cpe:2.3:a:nextcloud:nextcloud_server

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

nextcloud nextcloud server25.0.0 and later · before 25.0.3

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

nextcloud security-advisories
- >= 25.0.0, < 25.0.3affected

Same product

nextcloud: all records

Other highest-scoring records for the same primary product.

CVE-2023-26482Scope of workflow operations is not validated in nextcloud server
40Plan
CVE-2021-32802Preview generation used third-party library not suited for user-generated content in Nextcloud server
40Plan
CVE-2021-32726Webauthn tokens not removed after user has been deleted
40Plan

Published before and after this one in the same product

← EarlierCVE-2023-25162Feb 13, 2023 · Nextcloud Server vulnerable to SSRF via filter bypass due to lax checking on IPs
21Monitor
← EarlierCVE-2023-25579Feb 22, 2023 · Directory traversal in Nextcloud server
30Monitor
Later →CVE-2023-25821Feb 24, 2023 · Nextcloud download permissions can be changed by resharer
30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
nextcloud security-advisories	25.0.3 · description	Vendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

nextcloud/serverPR 35965

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

NextcloudHackerOne · paid

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: none
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: None
Availability impact: High

Weakness class (CWE)

CWE-400 · Uncontrolled Resource Consumption

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

The bug in code

The whole CWE-400 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1function expand(node) {
2  return node.children.map(expand);
3}

Fixed

1const MAX_DEPTH = 32;
2function expand(node, depth = 0) {
3  if (depth > MAX_DEPTH) throw new Error("too deep");
4  return node.children.map((c) => expand(c, depth + 1));
5}