CVE-2020-2040PAN-OS: Buffer overflow when Captive Portal or Multi-Factor Authentication (MFA) is enabled
- 9.8CriticalCVSS base score
- 3.9%Exploitation in 30 daysEPSS · top 9.5% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A buffer overflow vulnerability in PAN-OS allows an unauthenticated attacker to disrupt system processes and potentially execute arbitrary code with root privileges by sending a malicious request to the Captive Portal or Multi-Factor Authentication interface. This issue impacts: All versions of PAN-OS 8.0; PAN-OS 8.1 versions earlier than PAN-OS 8.1.15; PAN-OS 9.0 versions earlier than PAN-OS 9.0.9; PAN-OS 9.1 versions earlier than PAN-OS 9.1.3.
Timeline
ID reserved
By palo_alto
- 9 months later
· 9 months later
Published
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| palo_altoCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 3.9% · top 9.5% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
- affected 8.0.*
- affected 9.0 – < 9.0.9
- affected 9.1 – < 9.1.3
- affected 8.1 – < 8.1.15
- unaffected 10.0.0 – < 10.0*
What to do
Solution: This issue is fixed in PAN-OS 8.1.15, PAN-OS 9.0.9, PAN-OS 9.1.3, and all later PAN-OS versions. All Prisma Access services are now upgraded to resolve this issue and are no longer vulnerable. PAN-OS 7.1 and 8.0 are end-of-life and are no longer covered by our Product Security Assurance policies.
Workaround: Until PAN-OS software is upgraded to a fixed version, enabling signatures in content update version 8317 will block attacks against CVE-2020-2040.
Exploitation: Palo Alto Networks is not aware of any malicious attempts to exploit this vulnerability.
References
References1
- https://security.paloaltonetworks.com/CVE-2020-2040 (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2020-22066 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2020-2040)Record last updated .