CVE-2019-20892Network attack vector

Authenticated service crash via untracked USM ownership

Published Jun 25, 2020 · Updated Aug 5, 2024

Double free in net-snmp before 5.8.1.pre1 allows remote authenticated users to crash snmpd via a crafted SNMPv3 GetBulk request. PDU cloning reuses the same securityStateRef without reference counting, so cleanup paths release the same USM state allocation twice. The flaw requires authenticated SNMPv3 access and interrupts service availability; published evidence reports no data disclosure or modification.

CVSS severity6.5
Medium
EPSS probability2.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Double free in net-snmp before 5.8.1.pre1 allows remote authenticated users to crash snmpd via a crafted SNMPv3 GetBulk request. PDU cloning reuses the same securityStateRef without reference counting, so cleanup paths release the same USM state allocation twice. The flaw requires authenticated SNMPv3 access and interrupts service availability; published evidence reports no data disclosure or modification.

The record

CVE
CVE-2019-20892
Published
Jun 25, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-415, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 25, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.5CanonicalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.0NIST NVDAV:N/AC:L/Au:S/C:N/I:N/A:P

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-415Double Free
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo