NVD / CVE Program· CNA Linux

CVE-2021-47100: ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module

Noroxi assessment

Priority: Monitor (action score 22/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.24% (FIRST EPSS).
Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 6809da5185141e61401da5b01896b79a4deed1ad, 6b3f7e4b10f343f05b5fb513b07a9168fbf1172e, 925229d552724e1bba1abf01d3a0b1318539b012.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 6809da5185141e61401da5b01896b79a4deed1ad, 6b3f7e4b10f343f05b5fb513b07a9168fbf1172e, 925229d552724e1bba1abf01d3a0b1318539b012 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module Hi, When testing install and uninstall of ipmi_si.ko and ipmi_msghandler.ko, the system crashed. The log as follows: [ 141.087026] BUG: unable to handle kernel paging request at ffffffffc09b3a5a [ 141.087241] PGD 8fe4c0d067 P4D 8fe4c0d067 PUD 8fe4c0f067 PMD 103ad89067 PTE 0 [ 141.087464] Oops: 0010 [#1] SMP NOPTI [ 141.087580] CPU: 67 PID: 668 Comm: kworker/67:1 Kdump: loaded Not tainted 4.18.0.x86_64 #47 [ 141.088009] Workqueue: events 0xffffffffc09b3a40 [ 141.088009] RIP: 0010:0xffffffffc09b3a5a [ 141.088009] Code: Bad RIP value. [ 141.088009] RSP: 0018:ffffb9094e2c3e88 EFLAGS: 00010246 [ 141.088009] RAX: 0000000000000000 RBX: ffff9abfdb1f04a0 RCX: 0000000000000000 [ 141.088009] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246 [ 141.088009] RBP: 0000000000000000 R08: ffff9abfffee3cb8 R09: 00000000000002e1 [ 141.088009] R10: ffffb9094cb73d90 R11: 00000000000f4240 R12: ffff9abfffee8700 [ 141.088009] R13: 0000000000000000 R14: ffff9abfdb1f04a0 R15: ffff9abfdb1f04a8 [ 141.088009] FS: 0000000000000000(0000) GS:ffff9abfffec0000(0000) knlGS:0000000000000000 [ 141.088009] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 141.088009] CR2: ffffffffc09b3a30 CR3: 0000008fe4c0a001 CR4: 00000000007606e0 [ 141.088009] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 141.088009] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 141.088009] PKRU: 55555554 [ 141.088009] Call Trace: [ 141.088009] ? process_one_work+0x195/0x390 [ 141.088009] ? worker_thread+0x30/0x390 [ 141.088009] ? process_one_work+0x390/0x390 [ 141.088009] ? kthread+0x10d/0x130 [ 141.088009] ? kthread_flush_work_fn+0x10/0x10 [ 141.088009] ? ret_from_fork+0x35/0x40] BUG: unable to handle kernel paging request at ffffffffc0b28a5a [ 200.223240] PGD 97fe00d067 P4D 97fe00d067 PUD 97fe00f067 PMD a580cbf067 PTE 0 [ 200.223464] Oops: 0010 [#1] SMP NOPTI [ 200.223579] CPU: 63 PID: 664 Comm: kworker/63:1 Kdump: loaded Not tainted 4.18.0.x86_64 #46 [ 200.224008] Workqueue: events 0xffffffffc0b28a40 [ 200.224008] RIP: 0010:0xffffffffc0b28a5a [ 200.224008] Code: Bad RIP value. [ 200.224008] RSP: 0018:ffffbf3c8e2a3e88 EFLAGS: 00010246 [ 200.224008] RAX: 0000000000000000 RBX: ffffa0799ad6bca0 RCX: 0000000000000000 [ 200.224008] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246 [ 200.224008] RBP: 0000000000000000 R08: ffff9fe43fde3cb8 R09: 00000000000000d5 [ 200.224008] R10: ffffbf3c8cb53d90 R11: 00000000000f4240 R12: ffff9fe43fde8700 [ 200.224008] R13: 0000000000000000 R14: ffffa0799ad6bca0 R15: ffffa0799ad6bca8 [ 200.224008] FS: 0000000000000000(0000) GS:ffff9fe43fdc0000(0000) knlGS:0000000000000000 [ 200.224008] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 200.224008] CR2: ffffffffc0b28a30 CR3: 00000097fe00a002 CR4: 00000000007606e0 [ 200.224008] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 200.224008] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 200.224008] PKRU: 55555554 [ 200.224008] Call Trace: [ 200.224008] ? process_one_work+0x195/0x390 [ 200.224008] ? worker_thread+0x30/0x390 [ 200.224008] ? process_one_work+0x390/0x390 [ 200.224008] ? kthread+0x10d/0x130 [ 200.224008] ? kthread_flush_work_fn+0x10/0x10 [ 200.224008] ? ret_from_fork+0x35/0x40 [ 200.224008] kernel fault(0x1) notification starting on CPU 63 [ 200.224008] kernel fault(0x1) notification finished on CPU 63 [ 200.224008] CR2: ffffffffc0b28a5a [ 200.224008] ---[ end trace c82a412d93f57412 ]--- The reason is as follows: T1: rmmod ipmi_si. ->ipmi_unregister_smi() -> ipmi_bmc_unregister() -> __ipmi_bmc_unregister() -> kref_put(&bmc->usecount, cleanup_bmc_device); -> schedule_work(&bmc->remove_work); T2: rmmod ipmi_msghandl ---truncated---

MediumCVSS 5.5 · v3.1—No exploit Fix available

Published: Mar 4, 2024
Updated: Jun 17, 2026
EPSS: 0.2% · 15th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 22 / 40 · 5.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

linux linux kernel4.15 and later · before 4.19.223
linux linux kernel4.20 and later · before 5.4.169
linux linux kernel5.5 and later · before 5.10.89
linux linux kernel5.11 and later · before 5.15.12
linux linux kernel5.16

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- 4.15affected
- b2cfd8ab4add53c2070367bfee2f5b738f51698d and later · before 925229d552724e1bba1abf01d3a0b1318539b012affected · git
- b2cfd8ab4add53c2070367bfee2f5b738f51698d and later · before 992649b8b16843d27eb39ceea5f9cf85ffb50a18affected · git
- b2cfd8ab4add53c2070367bfee2f5b738f51698d and later · before 6809da5185141e61401da5b01896b79a4deed1adaffected · git
- b2cfd8ab4add53c2070367bfee2f5b738f51698d and later · before 6b3f7e4b10f343f05b5fb513b07a9168fbf1172eaffected · git
- b2cfd8ab4add53c2070367bfee2f5b738f51698d and later · before ffb76a86f8096a8206be03b14adda6092e18e275affected · git
- before 4.15not affected · semver
- 4.19.223 and later · up to and including 4.19.*not affected · semver
- 5.4.169 and later · up to and including 5.4.*not affected · semver
- 5.10.89 and later · up to and including 5.10.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 5.15.15-1	5.15.15-1
openSUSE:Leap 15.5	kernel-azure	before 5.14.21-150500.33.48.1	5.14.21-150500.33.48.1
openSUSE:Leap 15.5	kernel-source-azure	before 5.14.21-150500.33.48.1	5.14.21-150500.33.48.1
openSUSE:Leap 15.5	kernel-syms-azure	before 5.14.21-150500.33.48.1	5.14.21-150500.33.48.1
openSUSE:Leap Micro 5.3	kernel-default	before 5.14.21-150400.24.116.1	5.14.21-150400.24.116.1
openSUSE:Leap Micro 5.3	kernel-default-base	before 5.14.21-150400.24.116.1.150400.24.54.5	5.14.21-150400.24.116.1.150400.24.54.5
openSUSE:Leap Micro 5.3	kernel-rt	before 5.14.21-150400.15.76.1	5.14.21-150400.15.76.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS	kernel-64kb	before 5.14.21-150400.24.116.1	5.14.21-150400.24.116.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS	kernel-docs	before 5.14.21-150400.24.116.1	5.14.21-150400.24.116.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS	kernel-obs-build	before 5.14.21-150400.24.116.1	5.14.21-150400.24.116.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS	kernel-source	before 5.14.21-150400.24.116.1	5.14.21-150400.24.116.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS	kernel-syms	before 5.14.21-150400.24.116.1	5.14.21-150400.24.116.1
SUSE:Linux Enterprise Live Patching 15 SP4	kernel-livepatch-SLE15-SP4_Update_25	before 1-150400.9.5.1	1-150400.9.5.1
SUSE:Linux Enterprise Micro 5.1	kernel-rt	before 5.3.18-150300.211.1	5.3.18-150300.211.1
SUSE:Linux Enterprise Micro 5.1	kernel-source-rt	before 5.3.18-150300.211.1	5.3.18-150300.211.1
SUSE:Linux Enterprise Micro 5.3	kernel-default	before 5.14.21-150400.24.116.1	5.14.21-150400.24.116.1
SUSE:Linux Enterprise Micro 5.3	kernel-default-base	before 5.14.21-150400.24.116.1.150400.24.54.5	5.14.21-150400.24.116.1.150400.24.54.5
SUSE:Linux Enterprise Micro 5.3	kernel-rt	before 5.14.21-150400.15.76.1	5.14.21-150400.15.76.1
SUSE:Linux Enterprise Micro 5.3	kernel-source-rt	before 5.14.21-150400.15.76.1	5.14.21-150400.15.76.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP5	kernel-azure	before 5.14.21-150500.33.48.1	5.14.21-150500.33.48.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP5	kernel-source-azure	before 5.14.21-150500.33.48.1	5.14.21-150500.33.48.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP5	kernel-syms-azure	before 5.14.21-150500.33.48.1	5.14.21-150500.33.48.1
SUSE:Linux Enterprise Server 15 SP4-LTSS	kernel-zfcpdump	before 5.14.21-150400.24.116.1	5.14.21-150400.24.116.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
90Now
CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
89Now
CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
85Now

Published before and after this one in the same product

← EarlierCVE-2021-47098Mar 4, 2024 · hwmon: (lm90) Prevent integer overflow/underflow in hysteresis calculations
31Monitor
← EarlierCVE-2021-47099Mar 4, 2024 · veth: ensure skb entering GRO are not cloned.
31Monitor
Later →CVE-2021-47101Mar 4, 2024 · asix: fix uninit-value in asix_mdio_read()
28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	6809da5185141e61401da5b01896b79a4deed1ad	Vendor (CNA)
Linux Linux	6b3f7e4b10f343f05b5fb513b07a9168fbf1172e	Vendor (CNA)
Linux Linux	925229d552724e1bba1abf01d3a0b1318539b012	Vendor (CNA)
Linux Linux	992649b8b16843d27eb39ceea5f9cf85ffb50a18	Vendor (CNA)
Linux Linux	ffb76a86f8096a8206be03b14adda6092e18e275	Vendor (CNA)
debian:linux	5.15.15-1 · Debian:12	Package registry (OSV)
opensuse:kernel-azure	5.14.21-150500.33.48.1 · openSUSE:Leap 15.5	Package registry (OSV)
opensuse:kernel-default	5.14.21-150400.24.116.1 · openSUSE:Leap Micro 5.3	Package registry (OSV)
opensuse:kernel-default-base	5.14.21-150400.24.116.1.150400.24.54.5 · openSUSE:Leap Micro 5.3	Package registry (OSV)
opensuse:kernel-rt	5.14.21-150400.15.76.1 · openSUSE:Leap Micro 5.3	Package registry (OSV)
opensuse:kernel-source-azure	5.14.21-150500.33.48.1 · openSUSE:Leap 15.5	Package registry (OSV)
opensuse:kernel-syms-azure	5.14.21-150500.33.48.1 · openSUSE:Leap 15.5	Package registry (OSV)
suse:kernel-64kb	5.14.21-150400.24.116.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS	Package registry (OSV)
suse:kernel-azure	5.14.21-150500.33.48.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP5	Package registry (OSV)
suse:kernel-default	5.14.21-150400.24.116.1 · SUSE:Linux Enterprise Micro 5.3	Package registry (OSV)
suse:kernel-default-base	5.14.21-150400.24.116.1.150400.24.54.5 · SUSE:Linux Enterprise Micro 5.3	Package registry (OSV)
suse:kernel-docs	5.14.21-150400.24.116.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS	Package registry (OSV)
suse:kernel-livepatch-SLE15-SP4_Update_25	1-150400.9.5.1 · SUSE:Linux Enterprise Live Patching 15 SP4	Package registry (OSV)
suse:kernel-obs-build	5.14.21-150400.24.116.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS	Package registry (OSV)
suse:kernel-rt	5.14.21-150400.15.76.1 · SUSE:Linux Enterprise Micro 5.3	Package registry (OSV)
suse:kernel-source	5.14.21-150400.24.116.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS	Package registry (OSV)
suse:kernel-source-rt	5.14.21-150400.15.76.1 · SUSE:Linux Enterprise Micro 5.3	Package registry (OSV)
suse:kernel-syms	5.14.21-150400.24.116.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS	Package registry (OSV)
suse:kernel-zfcpdump	5.14.21-150400.24.116.1 · SUSE:Linux Enterprise Server 15 SP4-LTSS	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-24-0167 · Mar 5, 2024(Linux Kernel Güncellemesi)

All national notices →

Technical details

Attack conditions

Someone with local access to the system can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: none
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: None
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:11 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/6809da5185141e61401da5b01896b79a4deed1ad

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records