Skip to content
Noroxi
NVD / CVE Program· CNA mitre

CVE-2021-44733: A use-after-free exists in drivers/tee/tee_shm.c in the TEE subsystem in the Linux kernel through 5.15.11.

Noroxi assessment

Priority: Monitor (action score 28/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.74% (FIRST EPSS); higher than 54.8% of all records.
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: linux (Debian:12) 5.15.15-1; dtb-aarch64 (openSUSE:Leap 15.3) 5.3.18-150300.59.49.1; kernel-64kb (openSUSE:Leap 15.3) 5.3.18-150300.59.49.1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to linux (Debian:12) 5.15.15-1; dtb-aarch64 (openSUSE:Leap 15.3) 5.3.18-150300.59.49.1; kernel-64kb (openSUSE:Leap 15.3) 5.3.18-150300.59.49.1 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

A use-after-free exists in drivers/tee/tee_shm.c in the TEE subsystem in the Linux kernel through 5.15.11. This occurs because of a race condition in tee_shm_get_from_id during an attempt to free a shared memory object.

HighCVSS 7.0 · v3.1—Proof of concept Fix available
Published
Dec 22, 2021
Updated
Aug 5, 2026
EPSS
0.7% · 54th percentile

Report tools

JSON

Action score

28

Monitor

Low priority for now.

CVSS
28 / 40 · 7.0 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2021-44733

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

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.

VendorProduct
linuxlinux kernel
redhatenterprise linux
fedoraprojectfedora
debiandebian linux
netapph410c firmware
netapph410c
netapph300s firmware
netapph300s
netapph500s firmware
netapph500s
netapph700s firmware
netapph700s

and 8 more

Affected versions

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

  • debian debian linux10.0
  • debian debian linux11.0
  • debian debian linux9.0
  • fedoraproject fedora35
  • linux linux kernel5.11 and later · before 5.15.12
  • linux linux kernel4.12 and later · before 4.14.261
  • linux linux kernel4.15 and later · before 4.19.224
  • linux linux kernel4.20 and later · before 5.4.170
  • linux linux kernel5.5 and later · before 5.10.89
  • netapp h300e firmwareall versions
  • netapp h300s firmwareall versions
  • netapp h410c firmwareall versions
  • netapp h410s firmwareall versions
  • netapp h500e firmwareall versions
  • netapp h500s firmwareall versions
  • netapp h700e firmwareall versions
  • netapp h700s firmwareall versions
  • redhat enterprise linux8.0

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 5.15.15-15.15.15-1
openSUSE:Leap 15.3dtb-aarch64before 5.3.18-150300.59.49.15.3.18-150300.59.49.1
openSUSE:Leap 15.3kernel-64kbbefore 5.3.18-150300.59.49.15.3.18-150300.59.49.1
openSUSE:Leap 15.3kernel-azurebefore 5.3.18-150300.38.40.45.3.18-150300.38.40.4
openSUSE:Leap 15.3kernel-debugbefore 5.3.18-150300.59.49.15.3.18-150300.59.49.1
openSUSE:Leap 15.3kernel-defaultbefore 5.3.18-150300.59.49.15.3.18-150300.59.49.1
openSUSE:Leap 15.3kernel-default-basebefore 5.3.18-150300.59.49.1.150300.18.31.15.3.18-150300.59.49.1.150300.18.31.1
openSUSE:Leap 15.3kernel-docsbefore 5.3.18-150300.59.49.15.3.18-150300.59.49.1
openSUSE:Leap 15.3kernel-kvmsmallbefore 5.3.18-150300.59.49.15.3.18-150300.59.49.1
openSUSE:Leap 15.3kernel-obs-buildbefore 5.3.18-150300.59.49.15.3.18-150300.59.49.1
openSUSE:Leap 15.3kernel-obs-qabefore 5.3.18-150300.59.49.15.3.18-150300.59.49.1
openSUSE:Leap 15.3kernel-preemptbefore 5.3.18-150300.59.49.15.3.18-150300.59.49.1
openSUSE:Leap 15.3kernel-sourcebefore 5.3.18-150300.59.49.15.3.18-150300.59.49.1
openSUSE:Leap 15.3kernel-source-azurebefore 5.3.18-150300.38.40.45.3.18-150300.38.40.4
openSUSE:Leap 15.3kernel-symsbefore 5.3.18-150300.59.49.15.3.18-150300.59.49.1
openSUSE:Leap 15.3kernel-syms-azurebefore 5.3.18-150300.38.40.15.3.18-150300.38.40.1
openSUSE:Leap 15.3kernel-zfcpdumpbefore 5.3.18-150300.59.49.15.3.18-150300.59.49.1
SUSE:Linux Enterprise High Availability Extension 12 SP5kernel-defaultbefore 4.12.14-122.110.14.12.14-122.110.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-ESPOSkernel-default-basebefore 5.3.18-24.99.1.9.46.15.3.18-24.99.1.9.46.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-ESPOSkernel-docsbefore 5.3.18-24.99.15.3.18-24.99.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-ESPOSkernel-obs-buildbefore 5.3.18-24.99.15.3.18-24.99.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-ESPOSkernel-preemptbefore 5.3.18-24.99.15.3.18-24.99.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-ESPOSkernel-sourcebefore 5.3.18-24.99.15.3.18-24.99.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-ESPOSkernel-symsbefore 5.3.18-24.99.15.3.18-24.99.1

+35

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-2021-45095Dec 16, 2021 · pep_sock_accept in net/phonet/pep.c in the Linux kernel through 5.15.8 has a refcount leak.
    22Monitor
  • ← EarlierCVE-2021-45100Dec 16, 2021 · The ksmbd server through 3.4.2, as used in the Linux kernel through 5.15.8, sometimes communicates in cleartext even though encryption has b
    30Monitor
  • Later →CVE-2021-45469Dec 23, 2021 · In __f2fs_setxattr in fs/f2fs/xattr.c in the Linux kernel through 5.15.11, there is an out-of-bounds memory access when an inode has an inva
    31Monitor

Remediation

Which version to upgrade to

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

Product / packageFixed versionSource
debian:linux5.15.15-1 · Debian:12Package registry (OSV)
opensuse:dtb-aarch645.3.18-150300.59.49.1 · openSUSE:Leap 15.3Package registry (OSV)
opensuse:kernel-64kb5.3.18-150300.59.49.1 · openSUSE:Leap 15.3Package registry (OSV)
opensuse:kernel-azure5.3.18-150300.38.40.4 · openSUSE:Leap 15.3Package registry (OSV)
opensuse:kernel-debug5.3.18-150300.59.49.1 · openSUSE:Leap 15.3Package registry (OSV)
opensuse:kernel-default5.3.18-150300.59.49.1 · openSUSE:Leap 15.3Package registry (OSV)
opensuse:kernel-default-base5.3.18-150300.59.49.1.150300.18.31.1 · openSUSE:Leap 15.3Package registry (OSV)
opensuse:kernel-docs5.3.18-150300.59.49.1 · openSUSE:Leap 15.3Package registry (OSV)
opensuse:kernel-kvmsmall5.3.18-150300.59.49.1 · openSUSE:Leap 15.3Package registry (OSV)
opensuse:kernel-obs-build5.3.18-150300.59.49.1 · openSUSE:Leap 15.3Package registry (OSV)
opensuse:kernel-obs-qa5.3.18-150300.59.49.1 · openSUSE:Leap 15.3Package registry (OSV)
opensuse:kernel-source-azure5.3.18-150300.38.40.4 · openSUSE:Leap 15.3Package registry (OSV)
opensuse:kernel-syms-azure5.3.18-150300.38.40.1 · openSUSE:Leap 15.3Package registry (OSV)
suse:kernel-default5.3.18-24.99.1 · SUSE:Linux Enterprise Live Patching 15 SP2Package registry (OSV)
suse:kernel-default-base5.3.18-24.99.1.9.46.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-ESPOSPackage registry (OSV)
suse:kernel-docs5.3.18-24.99.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-ESPOSPackage registry (OSV)
suse:kernel-livepatch-SLE15-SP2_Update_231-5.3.1 · SUSE:Linux Enterprise Live Patching 15 SP2Package registry (OSV)
suse:kernel-obs-build5.3.18-24.99.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-ESPOSPackage registry (OSV)
suse:kernel-preempt5.3.18-24.99.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-ESPOSPackage registry (OSV)
suse:kernel-rt5.3.18-150300.71.1 · SUSE:Real Time Module 15 SP3Package registry (OSV)
suse:kernel-rt_debug5.3.18-150300.71.1 · SUSE:Real Time Module 15 SP3Package registry (OSV)
suse:kernel-source5.3.18-24.99.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-ESPOSPackage registry (OSV)
suse:kernel-source-rt5.3.18-150300.71.1 · SUSE:Real Time Module 15 SP3Package registry (OSV)
suse:kernel-syms5.3.18-24.99.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-ESPOSPackage registry (OSV)
suse:kernel-syms-rt5.3.18-150300.71.1 · SUSE:Real Time Module 15 SP3Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:762021-12-23

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.

  1. Published
  2. First PoCsame day
  3. TodayOct 30, 2026+1773 d

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

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

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.

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.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSS vector

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

nvd-primary

Attack context

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

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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

References

Show all references (5 more)

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

All records