Vulnerability Name:

CVE-2017-7820 (CCN-132759)

Assigned:2017-09-28
Published:2017-09-28
Updated:2019-10-03
Summary: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, possibly tricking the browser or extension into mishandling the element. This vulnerability affects Firefox < 56.
CVSS v3 Severity:5.3 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)
4.6 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): Low
Availibility (A): None
6.5 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N)
5.7 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): Required
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): High
Availibility (A): None
CVSS v2 Severity:5.0 Medium (CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:P/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): Partial
Availibility (A): None
6.8 Medium (CCN CVSS v2 Vector: AV:N/AC:L/Au:S/C:N/I:C/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): None
Integrity (I): Complete
Availibility (A): None
Vulnerability Type:CWE-noinfo
Vulnerability Consequences:Bypass Security
References:Source: MITRE
Type: CNA
CVE-2017-7820

Source: BID
Type: Third Party Advisory, VDB Entry
101057

Source: CCN
Type: BID-101057
Mozilla Firefox Multiple Security Vulnerabilities

Source: SECTRACK
Type: Third Party Advisory, VDB Entry
1039465

Source: CONFIRM
Type: Exploit, Issue Tracking
https://bugzilla.mozilla.org/show_bug.cgi?id=1378207

Source: XF
Type: UNKNOWN
firefox-cve20177820-sec-bypass(132759)

Source: CCN
Type: Mozilla Foundation Security Advisory 2017-21
Security vulnerabilities fixed in Firefox 56

Source: CONFIRM
Type: Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2017-21/

Vulnerable Configuration:Configuration 1:
  • cpe:/a:mozilla:firefox:*:*:*:*:*:*:*:* (Version <= 55.0.3)

    • Configuration CCN 1:
  • cpe:/a:mozilla:firefox:55.0:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:org.opensuse.security:def:20177820
    V
    		CVE-2017-7820
    2022-06-30
    oval:org.opensuse.security:def:111899
    P
    		MozillaFirefox-92.0-1.2 on GA media (Moderate)
    2022-01-17
    oval:org.opensuse.security:def:105476
    P
    		MozillaFirefox-92.0-1.2 on GA media (Moderate)
    2021-10-01
    oval:com.ubuntu.artful:def:20177820000
    V
    		CVE-2017-7820 on Ubuntu 17.10 (artful) - low.
    2018-06-11
    oval:com.ubuntu.bionic:def:20177820000
    V
    		CVE-2017-7820 on Ubuntu 18.04 LTS (bionic) - low.
    2018-06-11
    oval:com.ubuntu.bionic:def:201778200000000
    V
    		CVE-2017-7820 on Ubuntu 18.04 LTS (bionic) - low.
    2018-06-11
    oval:com.ubuntu.trusty:def:20177820000
    V
    		CVE-2017-7820 on Ubuntu 14.04 LTS (trusty) - low.
    2018-06-11
    oval:com.ubuntu.xenial:def:201778200000000
    V
    		CVE-2017-7820 on Ubuntu 16.04 LTS (xenial) - low.
    2018-06-11
    oval:com.ubuntu.xenial:def:20177820000
    V
    		CVE-2017-7820 on Ubuntu 16.04 LTS (xenial) - low.
    2018-06-11
    BACK
    mozilla firefox *
    mozilla firefox 55.0