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NVD / CVE Program· CNA Linux

CVE-2021-47401: ipack: ipoctal: fix stack information leak

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: 0.25% (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 0a9c36a2e06a249acbed64e8e0b84637c2ad7575, 2725925982dc96a78069cd118ea3d66759bfdad7, 5f6a309a699675680df15d9b6d389114515b4426.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0a9c36a2e06a249acbed64e8e0b84637c2ad7575, 2725925982dc96a78069cd118ea3d66759bfdad7, 5f6a309a699675680df15d9b6d389114515b4426 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: ipack: ipoctal: fix stack information leak The tty driver name is used also after registering the driver and must specifically not be allocated on the stack to avoid leaking information to user space (or triggering an oops). Drivers should not try to encode topology information in the tty device name but this one snuck in through staging without anyone noticing and another driver has since copied this malpractice. Fixing the ABI is a separate issue, but this at least plugs the security hole.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 21, 2024
Updated
Aug 5, 2026
EPSS
0.2% · 16th percentile

Report tools

JSON

Action score

22

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.

CNA vs NVD score

NVD
5.5
CNA · Linux
7.1
1.6 point gap

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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

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

Follow CVE-2021-47401

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

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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.

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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.

VendorProduct
linuxlinux kernel

Affected versions

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

  • linux linux kernel3.5 and later · before 4.4.286
  • linux linux kernel4.5 and later · before 4.9.285
  • linux linux kernel4.10 and later · before 4.14.249
  • linux linux kernel4.15 and later · before 4.19.209
  • linux linux kernel4.20 and later · before 5.4.151
  • linux linux kernel5.5 and later · before 5.10.71
  • linux linux kernel5.11 and later · before 5.14.10
  • linux linux kernel5.15

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

    • 3.5affected
    • ba4dc61fe8c545a5d6a68b63616776556b771f51 and later · before acb96e782bad427ca4bb1bd94af660acd1462380affected · git
    • ba4dc61fe8c545a5d6a68b63616776556b771f51 and later · before 741ea2670e021350e54f491106bdaa22dc50e6a0affected · git
    • ba4dc61fe8c545a5d6a68b63616776556b771f51 and later · before 2725925982dc96a78069cd118ea3d66759bfdad7affected · git
    • ba4dc61fe8c545a5d6a68b63616776556b771f51 and later · before 829f13d6079cf7a2465522f39acb43033e9b320daffected · git
    • ba4dc61fe8c545a5d6a68b63616776556b771f51 and later · before 8657158a3b68c85234e6da3d8eae33d6183588b7affected · git
    • ba4dc61fe8c545a5d6a68b63616776556b771f51 and later · before 5f6a309a699675680df15d9b6d389114515b4426affected · git
    • ba4dc61fe8c545a5d6a68b63616776556b771f51 and later · before 0a9c36a2e06a249acbed64e8e0b84637c2ad7575affected · git
    • ba4dc61fe8c545a5d6a68b63616776556b771f51 and later · before a89936cce87d60766a75732a9e7e25c51164f47caffected · git
    • before 3.5not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 5.14.12-15.14.12-1

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-2021-47399May 21, 2024 · ixgbe: Fix NULL pointer dereference in ixgbe_xdp_setup
    22Monitor
  • ← EarlierCVE-2021-47400May 21, 2024 · net: hns3: do not allow call hns3_nic_net_open repeatedly
    22Monitor
  • Later →CVE-2021-47402May 21, 2024 · net: sched: flower: protect fl_walk() with rcu
    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
Linux Linux0a9c36a2e06a249acbed64e8e0b84637c2ad7575Vendor (CNA)
Linux Linux2725925982dc96a78069cd118ea3d66759bfdad7Vendor (CNA)
Linux Linux5f6a309a699675680df15d9b6d389114515b4426Vendor (CNA)
Linux Linux741ea2670e021350e54f491106bdaa22dc50e6a0Vendor (CNA)
Linux Linux829f13d6079cf7a2465522f39acb43033e9b320dVendor (CNA)
Linux Linux8657158a3b68c85234e6da3d8eae33d6183588b7Vendor (CNA)
Linux Linuxa89936cce87d60766a75732a9e7e25c51164f47cVendor (CNA)
Linux Linuxacb96e782bad427ca4bb1bd94af660acd1462380Vendor (CNA)
debian:linux5.14.12-1 · Debian:12Package 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.

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.

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.

  • CVE-2025-22069330 days apartriscv: fgraph: Fix stack layout to match __arch_ftrace_regs argument of ftrace_return_to_handler
    31Monitor
  • CVE-2024-360329 days apartBluetooth: qca: fix info leak when fetching fw build id
    28Monitor
  • CVE-2024-360339 days apartBluetooth: qca: fix info leak when fetching board id
    28Monitor
  • CVE-2022-4875730 days apartnet: fix information leakage in /proc/net/ptype
    28Monitor
  • CVE-2024-3949952 days apartvmci: prevent speculation leaks by sanitizing event in event_deliver()
    28Monitor
  • CVE-2024-4388191 days apartwifi: ath12k: change DMA direction while mapping reinjected packets
    28Monitor

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.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-668 · Exposure of Resource to Wrong Sphere

CVSS vector

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

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.

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

Change log

  1. Fix✗ → ✓

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

References

Show all references (7 more)

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

All records