Security readout for executives and security teams
Plain-English summary
A Linux network-driver bug can crash affected systems using Broadcom 5760X-class hardware when the driver mishandles identifiers for combined packets. The supplied record rates it critical, although the documented failure is a kernel oops affecting availability; confidentiality and integrity impacts are not demonstrated in the bundle.
Executive priority
Treat affected production systems as an urgent availability risk, especially where a kernel crash would interrupt critical services. First confirm whether relevant Broadcom hardware and bnxt_en are present; systems without that combination are unlikely to be exposed based on the supplied evidence.
Technical view
On P7 hardware, bnxt_en treated a 12-bit GRO/LRO aggregation ID as 16 bits, allowing VLAN metadata bits to select the wrong TPA buffer. An invalid packet header can then reach __skb_pull() and trigger BUG(). The correction applies a 12-bit mask to P5_PLUS chips.
Likely exposure
Exposure appears limited to Linux systems using the bnxt_en driver with relevant P5_PLUS hardware, particularly 5760X/P7 adapters, and GRO/LRO processing. The supplied affected-version data references Linux 6.8 through later releases but is ambiguous; confirm status through the system vendor or distribution.
Exploitation context
The supplied record is not in CISA KEV and provides no evidence of active exploitation or a public exploit. Network adjacency is suggested by the CVSS vector and receive path, but the bundle does not establish that an unauthenticated attacker can reliably trigger the crash with crafted traffic.
Researcher notes
The demonstrated path is TPA-buffer misselection followed by an invalid SKB header and kernel BUG. The supplied CVSS 9.8 claims high confidentiality, integrity, and availability impact, but the narrative substantiates only a crash. Exact vulnerable and fixed release boundaries are unclear, so commit or vendor-backport verification is preferable.
Mitigation direction
- Install a vendor-supported kernel containing the linked aggregation-ID mask correction.
- Check Linux distribution advisories for the exact fixed package applicable to each system.
- Prioritize exposed, high-availability systems using bnxt_en with 5760X/P7 network adapters.
- Use vendor guidance for interim mitigations if immediate kernel updates are unavailable.
Validation and detection
- Inventory loaded bnxt_en drivers and identify installed Broadcom adapter models.
- Record running kernel and distribution package versions on potentially affected hosts.
- Confirm the installed kernel includes the relevant stable fix or vendor backport.
- Review kernel logs for bnxt_tpa_end, eth_type_trans, __skb_pull, BUG, or oops events.
- After updating, verify normal traffic processing and absence of recurring kernel faults.
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
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ATT&CK lookup starting points
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CVE-2024-56656 mapping review
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Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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
2 official scoresWe 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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9LinuxCVSS: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
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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/fe9274027697c69c1430dc7ee568f82b331ef972CVE reference, Linux
- https://git.kernel.org/stable/c/24c6843b7393ebc80962b59d7ae71af91bf0dcc1CVE 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.