CVE-2017-7820
The "instanceof" operator can bypass the Xray wrapper mechanism. When called on web content from the browser itself or an extension the web content can provide its own result for that operator,
02 Description
The "instanceof" operator can bypass the Xray wrapper mechanism. When called on web content from the browser itself or an extension the web content can provide its own result for that operator,
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- 1.16% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 66.7% of scored records. A rank, not a probability.
- NVD base score
- 5.3 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-17.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2018-06-11 21:00Z8 YR AGO
- Last updated
- 2024-08-05 16:12Z2 YR AGO
- Reserved
- 2017-04-12
- Assigning CNA
- mozilla
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- No CWE assigned
- Data version
- 5.1
- Document digest
- f6f0a9da8863947f4c708c12b164d2aafa6c4adca76bde4ad31bb8d865a24fd0
05 Affected products
06 References
- www.securitytracker.com1039465http://www.securitytracker.com/id/1039465
- bugzilla.mozilla.orghttps://bugzilla.mozilla.org/show_bug.cgi?id=1378207
- www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2017-21/
- www.securityfocus.com101057http://www.securityfocus.com/bid/101057
07 Fixed in
Ubuntu 14.04 LTS
- firefox Fixed in 56.0+build6-0ubuntu0.14.04.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 16.04 LTS
- firefox Fixed in 56.0+build6-0ubuntu0.16.04.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- firefox Fixed in 56.0+build6-0ubuntu1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.