Security readout for executives and security teams
Plain-English summary
CVE-2022-50258 is a Linux kernel bug in the Broadcom brcmfmac Wi-Fi driver. A firmware version string may lack a proper string terminator, causing the kernel to read beyond a stack buffer during device initialization. The provided sources do not show active exploitation or confirmed business impact beyond kernel memory-safety risk.
Executive priority
Treat this as a targeted kernel hardening update, not an emergency based on the supplied evidence. Prioritize laptops, embedded systems, and appliances using Broadcom Wi-Fi or accepting untrusted USB Wi-Fi devices.
Technical view
In brcmf_c_preinit_dcmds(), brcmfmac passes a firmware-populated buffer to strsep(). Because brcmf_fil_iovar_data_get() fills that buffer by memcpy(), it may not be null-terminated, producing a KASAN stack-out-of-bounds read. The upstream fix ensures the buffer is null-terminated before parsing.
Likely exposure
Exposure is most likely on Linux systems using the brcmfmac Broadcom Wi-Fi driver, particularly where affected kernel versions or unfixed stable branches are deployed. Systems without that driver, hardware, or module loaded are less likely exposed.
Exploitation context
The bundle says the issue was found with a modified syzkaller and includes a kernel crash trace during USB device probing. It does not cite KEV listing, public exploitation, exploit code, or confirmed real-world attacks.
Researcher notes
The vulnerable path is initialization-time parsing of firmware version data in brcmfmac. The source evidence supports an out-of-bounds read, not a proven privilege escalation or remote attack. Exploitability beyond crash or memory-safety impact is not established in the bundle.
Mitigation direction
- Update to a Linux kernel containing the referenced brcmfmac stable fixes.
- Check Linux distribution advisories for the exact fixed kernel package.
- Disable or avoid loading brcmfmac where Broadcom Wi-Fi is not required.
- Restrict untrusted physical or USB device access where applicable.
- Monitor kernel logs for brcmfmac initialization crashes or KASAN reports.
Validation and detection
- Inventory Linux hosts using the brcmfmac driver or Broadcom Wi-Fi hardware.
- Compare deployed kernel versions against vendor fixed kernel advisories.
- Confirm whether brcmfmac is loaded on production systems.
- Review crash logs for strsep or brcmf_c_preinit_dcmds traces.
- Verify patched kernels include the null-termination fix.
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
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CVE-2022-50258 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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.
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.
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/89243a7b0ea19606ba1c2873c9d569026ccb344fCVE reference, Linux
- https://git.kernel.org/stable/c/d481fd6064bf215d7c5068e15aa390c3b16c9cd0CVE reference, Linux
- https://git.kernel.org/stable/c/17dbe90e13f52848c460d253f15b765038ec6dc0CVE reference, Linux
- https://git.kernel.org/stable/c/d6ef66194bb4a6c18f5b9649bf62597909b040e4CVE reference, Linux
- https://git.kernel.org/stable/c/3a3a5e3f94068cd562d62a57da6983c8cd07d53cCVE reference, Linux
- https://git.kernel.org/stable/c/881f50d76c3892262730ddf5c894eb00310e736cCVE reference, Linux
- https://git.kernel.org/stable/c/ba166e0ebdde3dfa833f0a3edaf2b2934d4a87f7CVE reference, Linux
- https://git.kernel.org/stable/c/0a06cadcc2a0044e4a117cc0e61436fc3a0dad69CVE 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.