CVE-2020-35111: Medium severity thunderbird vulnerability

Published Dec 15, 2020
·
Updated

When an extension with the proxy permission registered to receive <allurls>, 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.

Affected Software

6 affected componentsFixes available
Mozilla Thunderbird<78.6
78.6
Mozilla Firefox<84.0
Mozilla Firefox ESR<78.6.0
Mozilla Thunderbird<78.6.0
Mozilla Firefox<84
84
Mozilla Firefox ESR<78.6
78.6

Event History

Dec 15, 2020
CVE Published
via Mozilla·12:00 AM
Jan 7, 2021
CVE Published
via MITRE·01:50 PM
Data Sourced
via MITRE·01:50 PM
DescriptionWeakness

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is CVE-2020-35111?

CVE-2020-35111 is a vulnerability in Mozilla Firefox and Thunderbird that allowed the proxy.onRequest callback to not be triggered for view-source URLs, potentially leading to IP address leakage.

2

Which products are affected by CVE-2020-35111?

Mozilla Firefox versions up to and exclusive of 84, Mozilla Thunderbird versions up to and exclusive of 78.6, and Mozilla Firefox ESR versions up to and exclusive of 78.6 are affected by CVE-2020-35111.

3

What is the severity of CVE-2020-35111?

CVE-2020-35111 is classified as a low severity vulnerability.

4

How can I remediate CVE-2020-35111?

To fix CVE-2020-35111, update to the latest version of Mozilla Firefox, Thunderbird, or Firefox ESR, depending on the product you are using.

5

Where can I find more information about CVE-2020-35111?

You can find more information about CVE-2020-35111 in the following references: [Mozilla Bugzilla - CVE-2020-35111](https://bugzilla.mozilla.org/show_bug.cgi?id=1657916), [Mozilla Security Advisory - MFSA2020-54](https://www.mozilla.org/en-US/security/advisories/mfsa2020-54/), [Mozilla Security Advisory - MFSA2020-56](https://www.mozilla.org/en-US/security/advisories/mfsa2020-56/).

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