Security readout for executives and security teams
Plain-English summary
CVE-2023-3773 is a Linux kernel information disclosure flaw in the XFRM packet transformation subsystem. A local user with CAP_NET_ADMIN could cause a small out-of-bounds read and potentially leak heap data to userspace. The issue is not remotely exploitable from the provided evidence and requires meaningful local privileges.
Executive priority
Treat as a moderate-priority kernel patching item. It is not supported as actively exploited in the provided sources, but it can expose sensitive memory on systems where local users or containers have elevated network administration capability.
Technical view
The flaw is CWE-125 in XFRM netlink attribute parsing. Improper handling of XFRMA_MTIMER_THRESH can allow a 4-byte out-of-bounds read. CVSS is 5.5 with local attack vector, low complexity, low privileges, no user interaction, and high confidentiality impact only.
Likely exposure
Red Hat lists RHEL 9 kernel packages, including kernel-rt, as affected, while RHEL 6, 7, and 8 entries are marked unaffected. Debian advisories are referenced, but this bundle does not enumerate exact Debian affected versions. Exposure is highest on multi-user or containerized Linux systems granting CAP_NET_ADMIN.
Exploitation context
The bundle does not show CISA KEV listing or active exploitation. Practical abuse requires local access plus CAP_NET_ADMIN, commonly present in privileged containers, network administration roles, or misconfigured service accounts. Impact is limited to confidentiality leakage, not integrity or availability, based on the provided CVSS vector.
Researcher notes
Focus validation on XFRM/netlink exposure and privilege boundaries, especially CAP_NET_ADMIN in containers. The provided evidence supports information disclosure only. Do not assume broader product impact or exploit availability beyond the Red Hat and Debian advisory references listed here.
Mitigation direction
- Apply the relevant Red Hat RHSA-2023:6583 kernel update where applicable.
- Review Debian DSA-5492 and Debian LTS guidance for Debian systems.
- Reduce CAP_NET_ADMIN grants to only services that require them.
- Reboot or otherwise activate updated kernels after patching.
- Prioritize privileged containers and shared Linux hosts first.
Validation and detection
- Inventory Linux hosts and map kernel packages to vendor advisory status.
- Confirm whether RHEL 9 systems run affected kernel or kernel-rt packages.
- Review container and service profiles for CAP_NET_ADMIN exposure.
- Verify scanners reference CVE-2023-3773 and vendor advisories accurately.
- Confirm updated kernels are active, not merely installed.
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-125: 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-2023-3773 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:H/I:N/A:N
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.
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:H/I:N/A:N1.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- RHSA-2023:6583CVE reference · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2023-3773CVE reference · vdb-entry, x_refsource_REDHAT
- RHBZ#2218944CVE reference · issue-tracking, x_refsource_REDHAT
- https://lists.debian.org/debian-lts-announce/2023/10/msg00027.htmlCVE reference · x_transferred
- https://www.debian.org/security/2023/dsa-5492CVE reference · x_transferred
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.
Out-of-bounds Read
Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.