CVE-2021-4115Public exploit

Local denial of service via file descriptor leak

Published Feb 21, 2022 · Updated Aug 3, 2024

Denial of service in Polkit 0.117 allows local users to crash the authorization daemon via file descriptor exhaustion. The polkit_system_bus_name_get_creds_sync function can leak an eventfd when D-Bus reply handling exits early, eventually exhausting the process descriptor limit. An unprivileged local account can trigger the leak without authentication to a network service; impact is limited to temporary Polkit service interruption while the process is reaped and respawned.

CVSS severity5.5
Medium
EPSS probability0.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Polkit 0.117 allows local users to crash the authorization daemon via file descriptor exhaustion. The polkit_system_bus_name_get_creds_sync function can leak an eventfd when D-Bus reply handling exits early, eventually exhausting the process descriptor limit. An unprivileged local account can trigger the leak without authentication to a network service; impact is limited to temporary Polkit service interruption while the process is reaped and respawned.

The record

CVE
CVE-2021-4115
Published
Feb 21, 2022
Updated
Aug 3, 2024
Vendor
Libslirp Project
Product
Polkit
Classifications
T1499.002
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 21, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.117

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Libslirp Project · Polkitversion=0.117

Published CVSS scores

2.1NVDAV:L/AC:L/Au:N/C:N/I:N/A:P
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499.002Service Exhaustion

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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