CVE-2020-1992Network attack vector

Root code execution via Varrcvr format string

Published Apr 8, 2020 · Updated Sep 17, 2024

Format string misuse in Palo Alto Networks PAN-OS 9.0 before 9.0.7 and 9.1 before 9.1.2 allows remote attackers to crash Varrcvr or run code as root. The Varrcvr daemon treats attacker-controlled input as a formatting directive instead of fixed data, permitting unsafe memory access during processing. Exposure requires a PA-7000 Series firewall with an installed and configured LFC and enabled WildFire services; other PA Series firewalls are unaffected.

CVSS severity8.1
High
EPSS probability3.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Format string misuse in Palo Alto Networks PAN-OS 9.0 before 9.0.7 and 9.1 before 9.1.2 allows remote attackers to crash Varrcvr or run code as root. The Varrcvr daemon treats attacker-controlled input as a formatting directive instead of fixed data, permitting unsafe memory access during processing. Exposure requires a PA-7000 Series firewall with an installed and configured LFC and enabled WildFire services; other PA Series firewalls are unaffected.

The record

CVE
CVE-2020-1992
Published
Apr 8, 2020
Updated
Sep 17, 2024
Vendor
Palo Alto Networks
Product
PAN-OS
Classifications
CWE-134, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 8, 2020CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=9.0 <9.0.7 changes=[{"at":"9.0.7","status":"unaffected"}]
  2. Affected versionversion=9.1 <9.1.2 changes=[{"at":"9.1.2","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Palo Alto Networks · PAN-OSversion=9.0 <9.0.7 changes=[{"at":"9.0.7","status":"unaffected"}]; version=9.1 <9.1.2 changes=[{"at":"9.1.2","status":"unaffected"}]

Published CVSS scores

9.3NVDAV:N/AC:M/Au:N/C:C/I:C/A:C
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.1Palo Alto NetworksCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-134Use of Externally-Controlled Format String
T1190Exploit Public-Facing Application

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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