CVE-2020-13775Network attack vector

Authenticated service crash via networkless status message

Published Jun 2, 2020 · Updated Aug 4, 2024

NULL pointer dereference in ZNC 1.8.0 through 1.8.1-rc1 allows remote authenticated users to crash the IRC bouncer. CClient::EchoMessage dereferences m_pNetwork while handling a PRIVMSG to the status pseudo-user without first verifying that the client has a network. Any authenticated ZNC account with echo-message disabled and no configured network can terminate the application, interrupting service for connected users.

CVSS severity6.5
Medium
EPSS probability1.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in ZNC 1.8.0 through 1.8.1-rc1 allows remote authenticated users to crash the IRC bouncer. CClient::EchoMessage dereferences m_pNetwork while handling a PRIVMSG to the status pseudo-user without first verifying that the client has a network. Any authenticated ZNC account with echo-message disabled and no configured network can terminate the application, interrupting service for connected users.

The record

CVE
CVE-2020-13775
Published
Jun 2, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-476, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 2, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 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
3.5NIST NVDAV:N/AC:M/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.

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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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
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

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Your stack

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