CVE-2020-35111

MEDIUM

4.3

CVSS Score

Published: January 7, 2021 at 01:50 PM UTC

Updated: June 17, 2026 at 03:13 AM UTC

3 products affected across 1 vendorFirefoxThunderbirdFirefox ESR

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Severity

MEDIUM4.3

Exploit prediction

EPSS 1%

Description

When an extension with the proxy permission registered to receive <all_urls>, the proxy.onRequest callback was not triggered for view-source URLs. While web content cannot navigate to such URLs, a user opening View Source could have inadvertently leaked their IP address. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Firefox · Mozilla

95%

v < 84

Affected range stops below 84, so it looks safe — our inference, not a vendor statement

Affected range stops below 84.0, so it looks safe — our inference, not a vendor statement

Firefox ESR · Mozilla

95%

v < 78.6

Affected range stops below 78.6, so it looks safe — our inference, not a vendor statement

Affected range stops below 78.6.0, so it looks safe — our inference, not a vendor statement

Thunderbird · Mozilla

95%

v < 78.6

Affected range stops below 78.6, so it looks safe — our inference, not a vendor statement

Affected range stops below 78.6.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (4)

x_refsource_MISCPermissions Required

Source: [email protected]

https://bugzilla.mozilla.org/show_bug.cgi?id=1657916

x_refsource_MISCVendor Advisory

Source: [email protected]

https://www.mozilla.org/security/advisories/mfsa2020-54/

x_refsource_MISCVendor Advisory

Source: [email protected]

https://www.mozilla.org/security/advisories/mfsa2020-55/

x_refsource_MISCVendor Advisory

Source: [email protected]

https://www.mozilla.org/security/advisories/mfsa2020-56/

CVSS

4.3MEDIUM[email protected]

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: REQUIRED
Scope: UNCHANGED
Confidentiality: LOW
Integrity: NONE
Availability: NONE

Vector?

Quick Info

StatusMODIFIED

CWE

NVD-CWE-noinfo

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