CVE-2017-7803
This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.96%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a 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.
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 1.96% probability · 80th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-269
- Affected
- redhat/enterprise linux desktop · redhat/enterprise linux server · redhat/enterprise linux server aus · redhat/enterprise linux server eus · redhat/enterprise linux workstation · debian/debian linux · mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
EPSS 2.0% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.securityfocus.com/bid/100234Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1039124Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2017:2456Third Party Advisory
- https://access.redhat.com/errata/RHSA-2017:2534Third Party Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1377426Exploit, Issue Tracking, Patch
- https://security.gentoo.org/glsa/201803-14Third Party Advisory
- https://www.debian.org/security/2017/dsa-3928Third Party Advisory
- https://www.debian.org/security/2017/dsa-3968Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-18/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-19/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-20/Vendor Advisory
- http://www.securityfocus.com/bid/100234Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1039124Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2017:2456Third Party Advisory
- https://access.redhat.com/errata/RHSA-2017:2534Third Party Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1377426Exploit, Issue Tracking, Patch
- https://security.gentoo.org/glsa/201803-14Third Party Advisory
- https://www.debian.org/security/2017/dsa-3928Third Party Advisory
- https://www.debian.org/security/2017/dsa-3968Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-18/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-19/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-20/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.