Advisory Published
CVE Published
Updated

CVE-2017-7789

First published: Tue Aug 08 2017(Updated: )

If a server sends two Strict-Transport-Security (STS) headers for a single connection, they will be rejected as invalid and HTTP Strict Transport Security (HSTS) will not be enabled for the connection.

Credit: security@mozilla.org

Affected SoftwareAffected VersionHow to fix
Firefox<55
55
Firefox<55.0

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Parent vulnerabilities

(Appears in the following advisories)

Frequently Asked Questions

  • What is the severity of CVE-2017-7789?

    CVE-2017-7789 is considered a moderate severity vulnerability affecting Firefox versions up to 55.

  • How do I fix CVE-2017-7789?

    To fix CVE-2017-7789, users should upgrade to Mozilla Firefox version 56 or later.

  • What does CVE-2017-7789 affect?

    CVE-2017-7789 affects Mozilla Firefox versions prior to 56, specifically relating to Strict-Transport-Security headers.

  • What happens if two STS headers are sent according to CVE-2017-7789?

    If a server sends two Strict-Transport-Security headers, they will be rejected as invalid and HSTS will not be enabled.

  • Is there a workaround for CVE-2017-7789?

    There is no specific workaround for CVE-2017-7789 other than upgrading to a secure version of Firefox.

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