CVE-2020-15679
An OAuth session fixation vulnerability existed in the VPN login flow, where an attacker could craft a custom login URL, convince a VPN…
- Published
- Updated
- Reserved
- Assigned by
- mozilla
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).
Timeline
ID reserved
By mozilla
- 2 years later
· 2 years later
Published
- 2 years later
· 2 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 |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | High7.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H |
| NVDNVD · Modified | 3.1 | High7.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H |
- EPSS (exploitation in 30 days)
- 0.51% · top 56% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.6.
Weakness
- OAuth Session Fixation on VPN login
- CWE-384 Session Fixation (opens in a new tab)All about CWE-384 and its CVEs
Affected products
Mozilla · Mozilla VPN iOS 1.0.7
- affected unspecified – < (929)
- affected unspecified – < 1.2.2
Mozilla · Mozilla VPN Android 1.1.0
- affected unspecified – < (1360)
References (4)
- https://www.mozilla.org/security/advisories/mfsa2020-48/ (opens in a new tab)x_transferred
- https://github.com/mozilla-services/guardian-vpn-windows/commit/ac6f562973a83f6758cd7ab7aa313e863047d41b (opens in a new tab)x_transferred
- https://github.com/mozilla-mobile/guardian-vpn-android/commit/981c840276ef3aee98cf5d42993d484ee99b28d9 (opens in a new tab)x_transferred
- https://github.com/mozilla-mobile/guardian-vpn-ios/commit/4309f5c9bd2c15cdfd39ac173665fad3f2598b54 (opens in a new tab)x_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)
- 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://trackcve.app/cve/CVE-2020-15679)Record last updated .