What’s Vulnerable › Vulnerabilities

CVE-2020-15679

• Severity: high (CVSS 7.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2022-12-22 · updated 2026-06-17
• Weakness: CWE-384

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).

Affected products

• Mozilla VPN 2.16.1: before 1.0.7_\(929\); before 1.2.2; from 1.0.7 before 1.0.7_\(929\); from 1.1.0 before 1.1.0_\(1360\) — fixed in 1.0.7_\(929\), 1.1.0_\(1360\), 1.2.2

How to fix

Upgrade to a fixed version: Mozilla VPN 2.16.1 1.0.7_\(929\), 1.1.0_\(1360\), 1.2.2. Check the vendor advisory for mitigations.

References

• https://github.com/mozilla-mobile/guardian-vpn-android/commit/981c840276ef3aee98cf5d42993d484ee99b28d9
• https://github.com/mozilla-mobile/guardian-vpn-ios/commit/4309f5c9bd2c15cdfd39ac173665fad3f2598b54
• https://github.com/mozilla-services/guardian-vpn-windows/commit/ac6f562973a83f6758cd7ab7aa313e863047d41b
• https://www.mozilla.org/security/advisories/mfsa2020-48/
• https://github.com/mozilla-mobile/guardian-vpn-android/commit/981c840276ef3aee98cf5d42993d484ee99b28d9
• https://github.com/mozilla-mobile/guardian-vpn-ios/commit/4309f5c9bd2c15cdfd39ac173665fad3f2598b54
• https://github.com/mozilla-services/guardian-vpn-windows/commit/ac6f562973a83f6758cd7ab7aa313e863047d41b
• https://www.mozilla.org/security/advisories/mfsa2020-48/

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