CVE-2019-20795

Local crash via freed netlink response access

Published May 9, 2020 · Updated Aug 5, 2024

Use-after-free in iproute2 before 5.1.0 allows local users to crash the ip utility while displaying network namespaces. get_netnsid_from_name frees the netlink response buffer before rta_getattr_u32 reads NETNSA_NSID through a pointer into that freed buffer. Reachability requires local high privileges and a crafted network namespace; nondefault setuid use and C library behavior further constrain the crash path.

CVSS severity4.4
Medium
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in iproute2 before 5.1.0 allows local users to crash the ip utility while displaying network namespaces. get_netnsid_from_name frees the netlink response buffer before rta_getattr_u32 reads NETNSA_NSID through a pointer into that freed buffer. Reachability requires local high privileges and a crafted network namespace; nondefault setuid use and C library behavior further constrain the crash path.

The record

CVE
CVE-2019-20795
Published
May 9, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-416
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. May 9, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

2.1NVDAV:L/AC:L/Au:N/C:N/I:N/A:P
4.4Canonical UbuntuCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
4.4SUSECVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
4.4NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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