How severe is CVE-2020-15679?

CVE-2020-15679 has a CVSS 3.x base score of 7.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability high.

Is CVE-2020-15679 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-15679?

CVE-2020-15679 primarily affects Mozilla Vpn. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-15679?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-15679 published?

CVE-2020-15679 was published on 2022-12-22 and last updated on 2026-06-17.

CVE-2020-15679

CVE-2020-15679 is a high-severity vulnerability in Mozilla Vpn with a CVSS 3.x base score of 7.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-384.

Key facts

Severity: High (CVSS 3.x base score 7.6)
EPSS exploit prediction: 0% (37th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-384
Affected product: Mozilla Vpn
Published: 2022-12-22
Last modified: 2026-06-17

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).

Frequently asked questions

What is 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 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).
How severe is CVE-2020-15679?: CVE-2020-15679 has a CVSS 3.x base score of 7.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability high.
Is CVE-2020-15679 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-15679?: CVE-2020-15679 primarily affects Mozilla Vpn. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-15679?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-15679 published?: CVE-2020-15679 was published on 2022-12-22 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:mozilla:vpn:*:*:*:*:*:iphone_os:*:*
cpe:2.3:a:mozilla:vpn:*:*:*:*:*:windows:*:*
cpe:2.3:a:mozilla:vpn:*:*:*:*:*:ipados:*:*
cpe:2.3:a:mozilla:vpn:*:*:*:*:*:android:*:*

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