Security readout for executives and security teams
Plain-English summary
This is a Linux kernel Wi-Fi driver flaw in Broadcom brcmfmac. A malformed channel list from a device can make the kernel read beyond an allocated buffer, risking sensitive memory disclosure or system crash. It is rated high, but the supplied sources do not show active exploitation.
Executive priority
Treat as a high-priority kernel maintenance issue for Linux assets using Broadcom Wi-Fi. It is not currently KEV-listed, so emergency response is not indicated from the supplied evidence, but patching should be scheduled promptly because impact includes kernel memory exposure and crash.
Technical view
brcmf_construct_chaninfo() and brcmf_enable_bw40_2g() trusted a device-supplied channel-spec count beyond list->element[] length, causing CWE-125 slab out-of-bounds reads. The fix adds count validation, frees the buffer, and returns -EINVAL, which callers handle. Syzkaller-derived testing triggered KASAN crashes during brcmfmac setup.
Likely exposure
Exposure is limited to Linux systems running vulnerable kernels with the Broadcom brcmfmac Wi-Fi driver in use. The provided data lists Linux kernel versions and stable commit references, but not distro package names or device-specific product SKUs.
Exploitation context
The CVSS vector is local, low complexity, low privileges, no user interaction, with high confidentiality and availability impact. KEV is false in the supplied bundle, and no cited source reports active exploitation. Evidence supports crash and out-of-bounds read conditions from fuzzing, not public weaponization.
Researcher notes
Focus review on brcmfmac channel information parsing and the stable commits adding count bounds checks. The affected-version data is broad and not mapped to distributions, so validation should use kernel commit ancestry, vendor advisories, or package changelogs rather than version strings alone.
Mitigation direction
- Update to a kernel or vendor package containing the listed stable fixes.
- Check Linux distribution advisories for backported brcmfmac fixes.
- Temporarily disable affected Broadcom Wi-Fi hardware or brcmfmac where feasible.
- Prioritize systems where untrusted users can attach or influence Wi-Fi hardware.
- Monitor vendor and CISA KEV updates for exploitation status changes.
Validation and detection
- Inventory Linux kernels and systems loading the brcmfmac driver.
- Confirm the relevant stable fix commit is present or backported.
- Check package changelogs for CVE-2022-49740 or brcmfmac count validation.
- Review kernel logs for brcmfmac probe crashes or KASAN reports.
- After updating, test Wi-Fi connectivity and driver initialization.
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-2022-49740 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
- High
- CVSS
- 7.1 (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: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:H/I:N/A:H1.85.2CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
7.1HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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/9cf5e99c1ae1a85286a76c9a970202750538394cCVE reference, Linux
- https://git.kernel.org/stable/c/b2e412879595821ff1b5545cbed5f108fba7f5b6CVE reference, Linux
- https://git.kernel.org/stable/c/e4991910f15013db72f6ec0db7038ea67a57052eCVE reference, Linux
- https://git.kernel.org/stable/c/f06de1bb6d61f0c18b0213bbc6298960037f9d42CVE reference, Linux
- https://git.kernel.org/stable/c/4920ab131b2dbae7464b72bdcac465d070254209CVE 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.
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.