Security readout for executives and security teams
Plain-English summary
This is a Linux kernel availability bug in the RZ/G2L watchdog driver. A 32-bit arithmetic overflow can produce an invalid timer value, potentially causing watchdog timeout handling to fail or behave incorrectly. It is local, requires low privileges, and affects availability rather than data confidentiality or integrity.
Executive priority
Treat this as a targeted availability risk, not a broad internet-facing emergency. Prioritize embedded or appliance fleets using the affected watchdog driver, especially where watchdog reliability supports recovery or uptime commitments.
Technical view
CVE-2022-49387 is a CWE-190 integer overflow in Linux kernel rzg2l_wdt. timer_cycle_us can become zero during maxval computation because 1024 was not promoted to 64-bit. The upstream fix appends ULL to force 64-bit arithmetic and also addresses an invalid min/max timeout warning.
Likely exposure
Exposure is most likely on Linux systems using affected 5.17/5.18-era kernels with the rzg2l_wdt watchdog driver present or enabled. General-purpose systems are less likely exposed unless this driver path is relevant. The provided affected-version data is limited and should be checked against vendor backports.
Exploitation context
The source bundle does not show active exploitation, and KEV is false. The CVSS vector indicates local access, low attack complexity, low privileges, no user interaction, unchanged scope, and high availability impact only.
Researcher notes
The evidence supports a local availability flaw caused by integer-width handling in watchdog timer calculations. Public sources name kernel stable commits but do not provide exploit details, affected downstream products, or standalone mitigations beyond applying the fix through kernel/vendor channels.
Mitigation direction
- Update to a kernel or vendor package containing the referenced stable fixes.
- Check distribution or embedded vendor advisories for backported patches.
- Prioritize systems where rzg2l_wdt is compiled, loaded, or required.
- Track remediation through normal kernel package management and firmware release processes.
Validation and detection
- Inventory kernels matching the affected version range or vendor backport status.
- Confirm whether the rzg2l_wdt driver is built, loaded, or used.
- Verify source or package includes one referenced stable kernel fix.
- Review logs for the cited invalid min/max watchdog warning.
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-190: 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-2022-49387 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/e07b9fa0dc32b492de85528caaf9f0c605d8424fCVE reference, Linux
- https://git.kernel.org/stable/c/b95a47667d34e76c2c9013f8e3b1e5039a5a0b76CVE reference, Linux
- https://git.kernel.org/stable/c/ea2949df22a533cdf75e4583c00b1ce94cd5a83bCVE 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.
Integer Overflow or Wraparound
Integer Overflow or Wraparound represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.