CVE-2020-1999

PAN-OS: Threat signatures are evaded by specifically crafted packets

At a glance

Severity
MEDIUM 5.3
EPSS
EPSS 1.34 % · percentile 71 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
palo_alto
NVD status
Modified

Description

A vulnerability exists in the Palo Alto Network PAN-OS signature-based threat detection engine that allows an attacker to communicate with devices in the network in a way that is not analyzed for threats by sending data through specifically crafted TCP packets. This technique evades signature-based threat detection. This issue impacts: PAN-OS 8.1 versions earlier than 8.1.17; PAN-OS 9.0 versions earlier than 9.0.11; PAN-OS 9.1 versions earlier than 9.1.5; All versions of PAN-OS 7.1 and PAN-OS 8.0.

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Npalo_alto
CVSS 3.1MEDIUM 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NNVD · psirt@paloaltonetworks.com (Secondary)
CVSS 3.1MEDIUM 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NNVD · nvd@nist.gov (Primary)
CVSS 2.0MEDIUM 5.0AV:N/AC:L/Au:N/C:N/I:P/A:NNVD · nvd@nist.gov (Primary)

Weaknesses (CWE)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Palo Alto Networks · PAN-OSaffected 7.1.* ; affected 8.0.* ; unaffected 10.0.* ; affected 8.1 < 8.1.17 ; affected 9.0 < 9.0.11 ; affected 9.1 < 9.1.5

References

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD