Security readout for executives and security teams
Plain-English summary
CVE-2023-53276 is a Linux kernel memory leak in UBIFS when temporary files are opened in encrypted directories. A local user could repeatedly trigger the leak and reduce system memory, potentially causing availability impact. This is not a remote takeover issue, and the provided sources do not show active exploitation.
Executive priority
Treat as routine-to-priority patching for affected Linux/UBIFS environments. Business risk is service disruption from memory exhaustion, not data theft or remote compromise. Prioritize embedded, appliance, or flash-storage systems using UBIFS, especially where untrusted local users or workloads exist.
Technical view
UBIFS tmpfile handling calls fscrypt_setup_filename for encrypted directories and fails to free allocated filename memory after copying it into the directory entry inode. The CVE maps to CWE-401 and CVSS 5.5, with local, low-privilege, no-user-interaction characteristics and high availability impact.
Likely exposure
Exposure is most likely on Linux systems using UBIFS with encrypted directories where local users or workloads can create temporary files. Many general-purpose servers may not use UBIFS. Confirm kernel version, UBIFS usage, filesystem encryption, and whether vendor kernels include the referenced stable fixes.
Exploitation context
The source describes a memory leak observed by kmemleak during tmpfile creation. Exploitation would require local ability to trigger the affected file operation. CISA KEV is false in the provided data, and no cited source reports active exploitation.
Researcher notes
The issue is a missing free in ubifs_tmpfile after fscrypt_setup_filename allocation. The record identifies the original affected lineage and multiple stable commit references. The affected-version data is not enough alone to determine every distribution kernel status; vendor backport verification is required.
Mitigation direction
- Apply Linux kernel updates containing the referenced UBIFS stable fixes.
- If using a vendor kernel, follow the vendor advisory and backport status.
- Prioritize systems using UBIFS with encrypted directories and local multi-user access.
- If patching is delayed, reduce unnecessary local access to affected systems.
Validation and detection
- Inventory Linux kernel versions across managed systems.
- Identify systems with UBIFS enabled or mounted.
- Check whether encrypted UBIFS directories are in use.
- Verify installed kernels include one of the referenced stable commits or vendor backports.
- Monitor memory pressure on suspected affected systems until patched.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-401: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2023-53276 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/8ad8c67a897e68426e85990ebfe0a7d1f71fc79fCVE reference, Linux
- https://git.kernel.org/stable/c/107d481642c356a5668058066360fc473911e628CVE reference, Linux
- https://git.kernel.org/stable/c/823f554747f8aafaa965fb2f3ae794110ed429efCVE reference, Linux
- https://git.kernel.org/stable/c/b8f444a4fadfb5070ed7e298e0a5ceb4a18014f3CVE reference, Linux
- https://git.kernel.org/stable/c/ce840284929b75dbbf062e0ce7fcb78a63b08b5eCVE reference, Linux
- https://git.kernel.org/stable/c/29738e1bcc799dd754711d4e4aab967f0c018175CVE reference, Linux
- https://git.kernel.org/stable/c/fd197308c0e4f738c7ea687d5332035c5753881cCVE reference, Linux
- https://git.kernel.org/stable/c/1e43d4284bdc3bd34bd770fea13910ac37ab0618CVE reference, Linux
- https://git.kernel.org/stable/c/1fb815b38bb31d6af9bd0540b8652a0d6fe6cfd3CVE reference, Linux
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Missing Release of Memory after Effective Lifetime
Missing Release of Memory after Effective Lifetime represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.