Cyber Resilience

CVE-2023-28834

Nextcloud Server 23.0.0 – 23.0.14

Public PoC
Published
03 April 2023
Modified
21 November 2024
Patch / 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 0.0081 54th percentile
Risk Priority 34 floored blend · peak EPSS

Summary

CVE-2023-28834 is a low-severity Improper Removal of Sensitive Information Before Storage or Transfer (CWE-212) vulnerability in Nextcloud Nextcloud Server. Its CVSS base score is 3.5 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Unsecured Credentials (T1552); ranked in the top 46% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability Data

Nextcloud Server is an open source personal cloud server. Nextcloud Server 24.0.0 until 24.0.6 and 25.0.0 until 25.0.4, as well as Nextcloud Enterprise Server 23.0.0 until 23.0.11, 24.0.0 until 24.0.6, and 25.0.0 until 25.0.4, have an information disclosure vulnerability. A…

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user was able to get the full data directory path of the Nextcloud server from an API endpoint. By itself this information is not problematic as it can also be guessed for most common setups, but it could speed up other unknown attacks in the future if the information is known. Nextcloud Server 24.0.6 and 25.0.4 and Nextcloud Enterprise Server 23.0.11, 24.0.6, and 25.0.4 contain patches for this issue. There are no known workarounds.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1552 Unsecured Credentials Credential Access
Adversaries may search compromised systems to find and obtain insecurely stored credentials.
T1552.001 Credentials In Files Credential Access
Adversaries may search local file systems and remote file shares for files containing insecurely stored credentials.
T1552.002 Credentials in Registry Credential Access
Adversaries may search the Registry on compromised systems for insecurely stored credentials.
T1552.004 Private Keys Credential Access
Adversaries may search for private key certificate files on compromised systems for insecurely stored credentials.
T1552.006 Group Policy Preferences Credential Access
Adversaries may attempt to find unsecured credentials in Group Policy Preferences (GPP).
T1003 OS Credential Dumping Credential Access
Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-48305Same product: Nextcloud Nextcloud Server
CVE-2024-52525Same product: Nextcloud Nextcloud Server
CVE-2023-45151Same product: Nextcloud Nextcloud Server
CVE-2024-52519Same product: Nextcloud Nextcloud Server
CVE-2025-66510Same product: Nextcloud Nextcloud Server
CVE-2023-25817Same product: Nextcloud Nextcloud Server
CVE-2024-52521Same product: Nextcloud Nextcloud Server
CVE-2024-52513Same product: Nextcloud Nextcloud Server
CVE-2024-52517Same product: Nextcloud Nextcloud Server
CVE-2024-52523Same product: Nextcloud Nextcloud Server

Affected Assets

nextcloud
nextcloud server
23.0.0 — 23.0.14 · 24.0.0 — 24.0.10 · 24.0.0 — 24.0.10

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V14.2.8
  • V14.3.3

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.

addresses: CWE-212

Eradication of spilled information from contaminated systems mitigates the effects of improper removal of sensitive data before storage or transfer.

addresses: CWE-212

The control requires verified removal of sensitive data before media is made available at a reduced classification level, directly addressing improper removal prior to storage or transfer.

addresses: CWE-212

Explicit procedures to delete inaccurate or outdated PII directly mitigate improper removal of sensitive information before storage or transfer.

addresses: CWE-212

Retention policies enforce removal or sanitization of sensitive data before storage or transfer per regulatory requirements.

addresses: CWE-212

The explicit requirement to delete inaccurate/outdated PII implements proper removal of sensitive information before further storage or transfer.

addresses: CWE-212

The control implements proper removal of sensitive information before storage or transfer of datasets.

addresses: CWE-212

The generate-on-demand-and-delete requirement enforces removal of sensitive information before storage or transfer, preventing improper retention.

addresses: CWE-212

Requires explicit removal of sensitive information prior to component transfer or disposal, reducing exposure from retained data.

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.

PR.DS-10 mostly match
prevents

Directly addresses removal of confidential data from process memory and similar in-use contexts before exposure.

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.

degrades

Explicit information-deletion control directly addresses improper removal of sensitive data.

prevents

Data-masking techniques can substitute for removal when full deletion is impractical.

prevents

Test-data protection rules require sanitization of production data used in testing.

prevents

Classification identifies sensitive data that must be removed before storage or transfer.

prevents

Information-transfer rules can require sanitization of sensitive content before sharing.

prevents

PII-protection requirements include removing identifiers before storage or disclosure.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (3 rules)
  • V-248579 OL 8 must restrict access to the kernel message buffer. prevents CWE-212
  • V-248580 OL 8 must prevent kernel profiling by unprivileged users. prevents CWE-212
  • V-248551 A sticky bit must be set on all OL 8 public directories to prevent unauthorized and unintended information transferred via shared system resources. prevents CWE-212
Oracle Linux 9 (1 rule)
  • V-271745 OL 9 must restrict access to the kernel message buffer. prevents CWE-212
RHEL 8 (1 rule)
  • V-230269 RHEL 8 must restrict access to the kernel message buffer. prevents CWE-212

References