CVE-2020-15679

Name: CVE-2020-15679
Creator: NVD / NIST
Published: 2022-12-22T20:15:10.73+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.6/10EPSS 0.47%

Last modified Jun 17, 2026

CVE-2020-15679 is a high-severity vulnerability rated 7.6/10 on the CVSS scale. An OAuth session fixation vulnerability existed in the VPN login flow, where an attacker could craft a custom login URL, convince a VPN user to login via that URL, and obtain authenticated access as that user. This issue is limited to cases where attacker and victim are sharing the same source IP and could allow the ability to view session states and disconnect VPN sessions. EPSS estimates a 0.47% chance of exploitation in the next 30 days.

Description

An OAuth session fixation vulnerability existed in the VPN login flow, where an attacker could craft a custom login URL, convince a VPN user to login via that URL, and obtain authenticated access as that user. This issue is limited to cases where attacker and victim are sharing the same source IP and could allow the ability to view session states and disconnect VPN sessions. This vulnerability affects Mozilla VPN iOS 1.0.7 < (929), Mozilla VPN Windows < 1.2.2, and Mozilla VPN Android 1.1.0 < (1360).

Metrics

CVSS 3.1

7.6/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H

EPSS Probability

0.47%

37.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Mozilla	Vpn	< 1.0.7_\(929\)
Mozilla	Vpn	< 1.2.2
Mozilla	Vpn	>= 1.0.7, < 1.0.7_\(929\)
Mozilla	Vpn	>= 1.1.0, < 1.1.0_\(1360\)

References

https://github.com/mozilla-mobile/guardian-vpn-android/commit/981c840276ef3aee98cf5d42993d484ee99b28d9Patch, Third Party Advisory
https://github.com/mozilla-mobile/guardian-vpn-ios/commit/4309f5c9bd2c15cdfd39ac173665fad3f2598b54Patch, Third Party Advisory
https://github.com/mozilla-services/guardian-vpn-windows/commit/ac6f562973a83f6758cd7ab7aa313e863047d41bPatch, Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2020-48/Vendor Advisory
https://github.com/mozilla-mobile/guardian-vpn-android/commit/981c840276ef3aee98cf5d42993d484ee99b28d9Patch, Third Party Advisory
https://github.com/mozilla-mobile/guardian-vpn-ios/commit/4309f5c9bd2c15cdfd39ac173665fad3f2598b54Patch, Third Party Advisory
https://github.com/mozilla-services/guardian-vpn-windows/commit/ac6f562973a83f6758cd7ab7aa313e863047d41bPatch, Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2020-48/Vendor Advisory

Timeline

Published: Dec 22, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-15679?

How severe is CVE-2020-15679?

CVE-2020-15679 has a CVSS score of 7.6/10 (HIGH severity). The EPSS model estimates a 0.47% probability of exploitation in the next 30 days.

How do I fix CVE-2020-15679?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-15679?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST