CVE-2020-2033

Pre-logon cookie disclosure via missing certificate validation

Published Jun 10, 2020 · Updated Sep 17, 2024

Improper certificate validation in Palo Alto Networks GlobalProtect App allows man-in-the-middle attackers to steal pre-logon cookies. The app fails to validate the server certificate during a pre-logon connection, exposing its authentication cookie when ARP manipulation redirects traffic. Enabled pre-logon and same-segment ARP control are required; affected 5.0 releases before 5.0.10 and 5.1 releases before 5.1.4 permit gateway access under pre-login user rules.

CVSS severity5.3
Medium
EPSS probability0.87%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper certificate validation in Palo Alto Networks GlobalProtect App allows man-in-the-middle attackers to steal pre-logon cookies. The app fails to validate the server certificate during a pre-logon connection, exposing its authentication cookie when ARP manipulation redirects traffic. Enabled pre-logon and same-segment ARP control are required; affected 5.0 releases before 5.0.10 and 5.1 releases before 5.1.4 permit gateway access under pre-login user rules.

The record

CVE
CVE-2020-2033
Published
Jun 10, 2020
Updated
Sep 17, 2024
Vendor
Palo Alto Networks
Product
GlobalProtect App
Classifications
CWE-290, CWE-295, T1557.002
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 10, 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=5.0 <5.0.10 changes=[{"at":"5.0.10","status":"unaffected"}]
  2. Affected versionversion=5.1 <5.1.4 changes=[{"at":"5.1.4","status":"unaffected"}]

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Palo Alto Networks · GlobalProtect Appversion=5.0 <5.0.10 changes=[{"at":"5.0.10","status":"unaffected"}]; version=5.1 <5.1.4 changes=[{"at":"5.1.4","status":"unaffected"}]

Published CVSS scores

5.3Palo Alto NetworksCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
2.9NIST NVDAV:A/AC:M/Au:N/C:P/I:N/A:N

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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-290Authentication Bypass by Spoofing
CWE-295Improper Certificate Validation
T1557.002Adversary-in-the-Middle: ARP Cache Poisoning

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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