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NVD / CVE Program· CNA Linux

CVE-2021-47086: phonet/pep: refuse to enable an unbound pipe

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: 0.22% (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 0bbdd62ce9d44f3a22059b3d20a0df977d9f6d59, 311601f114859d586d5ef8833d60d3aa23282161, 48c76fc53582e7f13c1e0b11c916e503256c4d0b.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0bbdd62ce9d44f3a22059b3d20a0df977d9f6d59, 311601f114859d586d5ef8833d60d3aa23282161, 48c76fc53582e7f13c1e0b11c916e503256c4d0b 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: phonet/pep: refuse to enable an unbound pipe This ioctl() implicitly assumed that the socket was already bound to a valid local socket name, i.e. Phonet object. If the socket was not bound, two separate problems would occur: 1) We'd send an pipe enablement request with an invalid source object. 2) Later socket calls could BUG on the socket unexpectedly being connected yet not bound to a valid object.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Mar 4, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 13th percentile
CWE
—

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.

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.

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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 kernelbefore 4.4.297
  • linux linux kernel4.5 and later · before 4.9.295
  • linux linux kernel4.10 and later · before 4.14.260
  • 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

    • 3.3affected
    • bdb6e697b2a76c541960b86ab8fda88f3de1adf2 and later · before 0bbdd62ce9d44f3a22059b3d20a0df977d9f6d59affected · git
    • bdb6e697b2a76c541960b86ab8fda88f3de1adf2 and later · before b10c7d745615a092a50c2e03ce70446d2bec2acaaffected · git
    • bdb6e697b2a76c541960b86ab8fda88f3de1adf2 and later · before 311601f114859d586d5ef8833d60d3aa23282161affected · git
    • bdb6e697b2a76c541960b86ab8fda88f3de1adf2 and later · before 982b6ba1ce626ef87e5c29f26f2401897554f235affected · git
    • bdb6e697b2a76c541960b86ab8fda88f3de1adf2 and later · before 48c76fc53582e7f13c1e0b11c916e503256c4d0baffected · git
    • bdb6e697b2a76c541960b86ab8fda88f3de1adf2 and later · before 52ad5da8e316fa11e3a50b3f089aa63e4089bf52affected · git
    • bdb6e697b2a76c541960b86ab8fda88f3de1adf2 and later · before 53ccdc73eedaf0e922c45b569b797d2796fbaafaaffected · git
    • bdb6e697b2a76c541960b86ab8fda88f3de1adf2 and later · before 75a2f31520095600f650597c0ac41f48b5ba0068affected · git
    • before 3.3not affected · semver

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 15.5dtb-aarch64before 5.14.21-150500.55.73.15.14.21-150500.55.73.1
openSUSE:Leap 15.5kernel-64kbbefore 5.14.21-150500.55.73.15.14.21-150500.55.73.1
openSUSE:Leap 15.5kernel-azurebefore 5.14.21-150500.33.63.15.14.21-150500.33.63.1
openSUSE:Leap 15.5kernel-debugbefore 5.14.21-150500.55.73.15.14.21-150500.55.73.1
openSUSE:Leap 15.5kernel-docsbefore 5.14.21-150500.55.73.25.14.21-150500.55.73.2
openSUSE:Leap 15.5kernel-kvmsmallbefore 5.14.21-150500.55.73.15.14.21-150500.55.73.1
openSUSE:Leap 15.5kernel-obs-buildbefore 5.14.21-150500.55.73.15.14.21-150500.55.73.1
openSUSE:Leap 15.5kernel-obs-qabefore 5.14.21-150500.55.73.15.14.21-150500.55.73.1
openSUSE:Leap 15.5kernel-rt_debugbefore 5.14.21-150500.13.64.15.14.21-150500.13.64.1
openSUSE:Leap 15.5kernel-sourcebefore 5.14.21-150500.55.73.15.14.21-150500.55.73.1
openSUSE:Leap 15.5kernel-source-azurebefore 5.14.21-150500.33.63.15.14.21-150500.33.63.1
openSUSE:Leap 15.5kernel-source-rtbefore 5.14.21-150500.13.64.15.14.21-150500.13.64.1
openSUSE:Leap 15.5kernel-symsbefore 5.14.21-150500.55.73.15.14.21-150500.55.73.1
openSUSE:Leap 15.5kernel-syms-azurebefore 5.14.21-150500.33.63.15.14.21-150500.33.63.1
openSUSE:Leap 15.5kernel-syms-rtbefore 5.14.21-150500.13.64.15.14.21-150500.13.64.1
openSUSE:Leap 15.5kernel-zfcpdumpbefore 5.14.21-150500.55.73.15.14.21-150500.55.73.1
openSUSE:Leap Micro 5.5kernel-defaultbefore 5.14.21-150500.55.73.15.14.21-150500.55.73.1
openSUSE:Leap Micro 5.5kernel-default-basebefore 5.14.21-150500.55.73.1.150500.6.33.85.14.21-150500.55.73.1.150500.6.33.8
openSUSE:Leap Micro 5.5kernel-rtbefore 5.14.21-150500.13.64.15.14.21-150500.13.64.1
SUSE:Linux Enterprise Live Patching 15 SP5kernel-livepatch-SLE15-SP5_Update_17before 1-150500.11.3.11-150500.11.3.1
SUSE:Linux Enterprise Live Patching 15 SP5kernel-livepatch-SLE15-SP5-RT_Update_18before 1-150500.11.3.11-150500.11.3.1
SUSE:Linux Enterprise Micro 5.5kernel-defaultbefore 5.14.21-150500.55.73.15.14.21-150500.55.73.1
SUSE:Linux Enterprise Micro 5.5kernel-default-basebefore 5.14.21-150500.55.73.1.150500.6.33.85.14.21-150500.55.73.1.150500.6.33.8

+13

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-2021-47082Mar 4, 2024 · tun: avoid double free in tun_free_netdev
    31Monitor
  • ← EarlierCVE-2021-47083Mar 4, 2024 · pinctrl: mediatek: fix global-out-of-bounds issue
    28Monitor
  • Later →CVE-2021-47087Mar 4, 2024 · tee: optee: Fix incorrect page free bug
    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 Linux0bbdd62ce9d44f3a22059b3d20a0df977d9f6d59Vendor (CNA)
Linux Linux311601f114859d586d5ef8833d60d3aa23282161Vendor (CNA)
Linux Linux48c76fc53582e7f13c1e0b11c916e503256c4d0bVendor (CNA)
Linux Linux52ad5da8e316fa11e3a50b3f089aa63e4089bf52Vendor (CNA)
Linux Linux53ccdc73eedaf0e922c45b569b797d2796fbaafaVendor (CNA)
Linux Linux75a2f31520095600f650597c0ac41f48b5ba0068Vendor (CNA)
Linux Linux982b6ba1ce626ef87e5c29f26f2401897554f235Vendor (CNA)
Linux Linuxb10c7d745615a092a50c2e03ce70446d2bec2acaVendor (CNA)
debian:linux5.15.15-1 · Debian:12Package registry (OSV)
opensuse:dtb-aarch645.14.21-150500.55.73.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-64kb5.14.21-150500.55.73.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-debug5.14.21-150500.55.73.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-default5.14.21-150500.55.73.1 · openSUSE:Leap Micro 5.5Package registry (OSV)
opensuse:kernel-default-base5.14.21-150500.55.73.1.150500.6.33.8 · openSUSE:Leap Micro 5.5Package registry (OSV)
opensuse:kernel-docs5.14.21-150500.55.73.2 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-kvmsmall5.14.21-150500.55.73.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-obs-build5.14.21-150500.55.73.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-rt5.14.21-150500.13.64.1 · openSUSE:Leap Micro 5.5Package registry (OSV)
opensuse:kernel-rt_debug5.14.21-150500.13.64.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-source-rt5.14.21-150500.13.64.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-syms-rt5.14.21-150500.13.64.1 · openSUSE:Leap 15.5Package registry (OSV)
suse:kernel-64kb5.14.21-150500.55.73.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP5Package registry (OSV)
suse:kernel-default5.14.21-150500.55.73.1 · SUSE:Linux Enterprise Micro 5.5Package registry (OSV)
suse:kernel-default-base5.14.21-150500.55.73.1.150500.6.33.8 · SUSE:Linux Enterprise Micro 5.5Package registry (OSV)
suse:kernel-docs5.14.21-150500.55.73.2 · SUSE:Linux Enterprise Module for Development Tools 15 SP5Package registry (OSV)
suse:kernel-livepatch-SLE15-SP5-RT_Update_181-150500.11.3.1 · SUSE:Linux Enterprise Live Patching 15 SP5Package registry (OSV)
suse:kernel-obs-build5.14.21-150500.55.73.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP5Package registry (OSV)
suse:kernel-rt5.14.21-150500.13.64.1 · SUSE:Linux Enterprise Micro 5.5Package registry (OSV)
suse:kernel-rt_debug5.14.21-150500.13.64.1 · SUSE:Real Time Module 15 SP5Package registry (OSV)
suse:kernel-source5.14.21-150500.55.73.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP5Package registry (OSV)

+3

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.

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.
  • 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)

—

CVSS vector

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

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