Security Resilience

CVE-2023-33184

SSRF in Nextcloud Mail 1.13.0 – 1.15.3

SSRF
Published
27 May 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 3.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
EPSS Score 0.0053 43th percentile
Risk Priority 32 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-33184 is a low-severity SSRF (CWE-918) vulnerability in Nextcloud Mail. Its CVSS base score is 3.5 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique LSASS Memory (T1003.001); ranked at the 43th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access Control

EU & UK References

Vulnerability Data

Nextcloud Mail is a mail app in Nextcloud. A blind SSRF attack allowed to send GET requests to services running in the same web server. It is recommended that the Mail app is update to version 3.02, 2.2.5 or 1.15.3.

CWE(s)
CWE-918

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
attack.mitre.org →
T1003.005 Cached Domain Credentials Credential Access
Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.
attack.mitre.org →
T1021.001 Remote Desktop Protocol Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
attack.mitre.org →
T1021.002 SMB/Windows Admin Shares Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
attack.mitre.org →
T1021.004 SSH Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
attack.mitre.org →
T1021.007 Cloud Services Lateral Movement
Adversaries may log into accessible cloud services within a compromised environment using [Valid Accounts](https://attack.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-48307Same product: Nextcloud Mail
CVE-2023-23943Same product: Nextcloud Mail
CVE-2023-45660Same product: Nextcloud Mail
CVE-2023-25160Same product: Nextcloud Mail
CVE-2023-23944Same product: Nextcloud Mail
CVE-2024-52508Same product: Nextcloud Mail
CVE-2025-66514Same product: Nextcloud Mail
CVE-2024-52509Same product: Nextcloud Mail
CVE-2023-48306Same vendor: Nextcloud
CVE-2023-25162Same vendor: Nextcloud

Affected Assets

nextcloud
mail
1.13.0 — 1.15.3 · 2.2.0 — 2.2.5 · 2.3.0 — 3.0.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.3.6
  • V1.5.3
  • V5.3.2
  • V10.4.7

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

CA-8 Penetration Testing
addresses: CWE-918

Penetration testing attempts server-side requests to internal resources, identifying SSRF weaknesses for remediation.

SC-7 Boundary Protection
addresses: CWE-918

Outbound connections to external resources can be monitored and limited at the boundary, reducing SSRF impact.

SI-10 Information Input Validation
addresses: CWE-918

Validates server-side URLs and resource references to block SSRF attempts.

SI-4 System Monitoring
addresses: CWE-918

Detects server-side request forgery through monitoring of unexpected outbound connections.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

DE.CM-09 partial match
blocks

Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.

ID.RA-01 partial match
blocks

Vulnerability identification processes can discover and record SSRF flaws in web applications.

PR.IR-01 partial match
blocks

Network segmentation and egress controls can limit the damage from successful SSRF requests.

PR.PS-06 partial match
blocks

Secure development practices directly include input validation and destination allow-listing that prevent SSRF.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.1 Policies for information security partial match
removes
A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes

References