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CVE Record

CVE-2021-47095: ipmi: ssif: initialize ssif_info->client early

In the Linux kernel, the following vulnerability has been resolved: ipmi: ssif: initialize ssif_info->client early During probe ssif_info->client is dereferenced in error path. However, it is set when some of the error checking has already been done. This causes following kernel crash if an error path is taken: [ 30.645593][ T674] ipmi_ssif 0-000e: ipmi_ssif: Not probing, Interface already present [ 30.657616][ T674] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000088 ... [ 30.657723][ T674] pc : __dev_printk+0x28/0xa0 [ 30.657732][ T674] lr : _dev_err+0x7c/0xa0 ... [ 30.657772][ T674] Call trace: [ 30.657775][ T674] __dev_printk+0x28/0xa0 [ 30.657778][ T674] _dev_err+0x7c/0xa0 [ 30.657781][ T674] ssif_probe+0x548/0x900 [ipmi_ssif 62ce4b08badc1458fd896206d9ef69a3c31f3d3e] [ 30.657791][ T674] i2c_device_probe+0x37c/0x3c0 ... Initialize ssif_info->client before any error path can be taken. Clear i2c_client data in the error path to prevent the dangling pointer from leaking.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue can crash a system during IPMI SSIF driver probing when an error path references an uninitialized client pointer. The business risk is primarily availability for systems using this driver, not confirmed data theft or privilege escalation from the provided sources.

Executive priority

Treat this as a targeted availability risk for Linux systems using IPMI SSIF. Prioritize patching where server management interfaces are present, but do not escalate as internet-wide emergency based on the provided evidence.

Technical view

In the Linux ipmi_ssif driver, ssif_info->client was assigned after some probe error checks. If an early error path ran, logging dereferenced a NULL client pointer, causing a kernel NULL pointer dereference. The fix initializes the client earlier and clears i2c_client data on error.

Likely exposure

Exposure is most likely on Linux systems running affected kernel versions with the ipmi_ssif driver active or probing IPMI SSIF devices. The source bundle lists Linux 5.4, 5.4.169, 5.10.89, 5.15.12, and 5.16 as affected evidence points.

Exploitation context

The provided sources do not show active exploitation, KEV listing, exploit code, or a remote attack path. They describe a probe-time kernel crash when a driver error path is reached, including an example where an interface was already present.

Researcher notes

Evidence is limited to the CVE record and kernel stable commit references. No CVSS, CWE, exploitability assessment, or distribution-specific fixed versions are provided in the bundle, so validation should focus on kernel lineage and driver presence.

Mitigation direction

  • Upgrade to a kernel containing the referenced stable fixes.
  • Use your Linux distribution’s security backports where available.
  • Check vendor advisories for exact fixed package versions.
  • Prioritize systems that load or probe the ipmi_ssif driver.

Validation and detection

  • Inventory kernels and identify systems using ipmi_ssif.
  • Check kernel changelogs for the referenced stable commits.
  • Review boot and kernel logs for ipmi_ssif NULL pointer crashes.
  • Confirm updated systems no longer reproduce probe-time crashes.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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-2021-47095 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
3Timeline events
2ADP providers
5Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxc4436c9149c5d2bc0c49ab57ec85c75ea1c4d61c, c4436c9149c5d2bc0c49ab57ec85c75ea1c4d61c, c4436c9149c5d2bc0c49ab57ec85c75ea1c4d61c, c4436c9149c5d2bc0c49ab57ec85c75ea1c4d61cunaffected
LinuxLinux5.4, 0, 5.4.169, 5.10.89, 5.15.12, 5.16affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.