CVE-2017-7803

Public Exploit

Description

When a page's content security policy (CSP) header contains a "sandbox" directive, other directives are ignored. This results in the incorrect enforcement of CSP. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.

Category

7.5
CVSS
Severity: High
CVSS 3.0 •
CVSS 2.0 •
EPSS 1.10% Top 25%
Vendor Advisory debian.org Vendor Advisory redhat.com Vendor Advisory redhat.com Vendor Advisory gentoo.org Vendor Advisory debian.org Vendor Advisory mozilla.org Vendor Advisory mozilla.org Vendor Advisory mozilla.org
Affected: Mozilla Thunderbird
Affected: Mozilla Firefox ESR
Affected: Mozilla Firefox
Published at:
Updated at:

References

Link Tags
https://www.mozilla.org/security/advisories/mfsa2017-19/ vendor advisory
https://www.mozilla.org/security/advisories/mfsa2017-20/ vendor advisory
https://www.debian.org/security/2017/dsa-3968 third party advisory vendor advisory
https://www.mozilla.org/security/advisories/mfsa2017-18/ vendor advisory
https://access.redhat.com/errata/RHSA-2017:2456 third party advisory vendor advisory
http://www.securityfocus.com/bid/100234 vdb entry third party advisory
https://access.redhat.com/errata/RHSA-2017:2534 third party advisory vendor advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1377426 issue tracking exploit patch
http://www.securitytracker.com/id/1039124 vdb entry third party advisory
https://security.gentoo.org/glsa/201803-14 third party advisory vendor advisory
https://www.debian.org/security/2017/dsa-3928 third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2017-7803?
CVE-2017-7803 has been scored as a high severity vulnerability.
How to fix CVE-2017-7803?
To fix CVE-2017-7803, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2017-7803 being actively exploited in the wild?
It is possible that CVE-2017-7803 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2017-7803?
CVE-2017-7803 affects Mozilla Thunderbird, Mozilla Firefox ESR, Mozilla Firefox.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.