CVE-2023-45660Network attack vector

Authenticated service interruption via unchecked image proxy

Published Oct 16, 2023 · Updated Sep 13, 2024

SSRF in Nextcloud Mail before 2.2.8 and before 3.3.0 allows remote authenticated users to interrupt a third-party server. The image proxy endpoint accepted external-image targets without strictly checking the request origin, destination, and required cookies before fetching them. A Mail account and an HTML message containing external images are required, and the reported consequence is limited to availability of the selected third-party service.

CVSS severity4.3
Medium
EPSS probability0.60%
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

SSRF in Nextcloud Mail before 2.2.8 and before 3.3.0 allows remote authenticated users to interrupt a third-party server. The image proxy endpoint accepted external-image targets without strictly checking the request origin, destination, and required cookies before fetching them. A Mail account and an HTML message containing external images are required, and the reported consequence is limited to availability of the selected third-party service.

The record

CVE
CVE-2023-45660
Published
Oct 16, 2023
Updated
Sep 13, 2024
Vendor
Nextcloud GmbH
Product
Security Advisories
Classifications
CWE-918, T1498
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 16, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 13, 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=>= 2.0.0, < 2.2.8
  2. Affected versionversion=>= 3.0.0, < 3.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Nextcloud GmbH · Security Advisoriesversion=>= 2.0.0, < 2.2.8; version=>= 3.0.0, < 3.3.0

Published CVSS scores

4.3NISTCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
4.3GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1498Network Denial of Service

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