CVE-2023-28834
Nextcloud Server 23.0.0 – 23.0.14
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
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 OS Credential Dumping (T1003); ranked in the top 44% 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
- 🇪🇺 ENISA EUVD: EUVD-2023-32466
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…
more
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
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
—
—
- 5 hardening rules · 3 OS baselines
V14.2.8V14.3.3
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.
Eradication of spilled information from contaminated systems mitigates the effects of improper removal of sensitive data before storage or transfer.
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.
Explicit procedures to delete inaccurate or outdated PII directly mitigate improper removal of sensitive information before storage or transfer.
Retention policies enforce removal or sanitization of sensitive data before storage or transfer per regulatory requirements.
The explicit requirement to delete inaccurate/outdated PII implements proper removal of sensitive information before further storage or transfer.
The control implements proper removal of sensitive information before storage or transfer of datasets.
The generate-on-demand-and-delete requirement enforces removal of sensitive information before storage or transfer, preventing improper retention.
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.
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.
A.5.12 only defines and communicates a classification scheme so that protection needs can be understood; per the owner's explicit rule on labelling/classification controls, it has no direct preventing effect on a weakness unless and until another control (access, DLP, etc.) is configured to act on the resulting label.
Information-transfer rules can require sanitization of sensitive content before sharing.
A.5.34 only requires a privacy policy, procedures, assigned roles (e.g. privacy officer) and unspecified technical/organizational measures; it does not itself stop the improper retention of sensitive data before storage/transfer, so the weakness remains exploitable without depending on other controls.
A.8.10 mandates configuring systems for automatic secure deletion (overwriting, crypto erase, approved tools/providers) of sensitive data no longer required per retention policy, which stops most improper-removal cases from leaving recoverable sensitive information available to unauthorized actors; the bounded remainder is deletion of in-transit/temporary buffers or non-configurable embedded device memory where the control's automation and method selection do not reach.
A.8.11's masking/pseudonymization/anonymization techniques (plus access design and obfuscation rules) stop most exposures of the sensitive data that CWE-212 would otherwise transfer or store in the clear; the bounded remainder is data that must stay unmasked for functional reasons or where masking is not applied to every indirect identifier.
DLP policies can block or sanitize sensitive data before it leaves the system.
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` (higher-evidence rows only; rows rated `none` are excluded).
Oracle Linux 8 (3 rules)
- V-248579 OL 8 must restrict access to the kernel message buffer. blocks CWE-212
- V-248580 OL 8 must prevent kernel profiling by unprivileged users. blocks 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. blocks CWE-212
Oracle Linux 9 (1 rule)
- V-271745 OL 9 must restrict access to the kernel message buffer. blocks CWE-212
RHEL 8 (1 rule)
- V-230269 RHEL 8 must restrict access to the kernel message buffer. blocks CWE-212