Improper input validation in Mozilla Firefox
Priority LOW 36CWE-20Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat.
Summary
File downloads encoded with "blob:" and "data:" URL elements bypassed normal file download checks though the Phishing and Malware Protection feature and its block lists of suspicious sites and files. This would allow malicious sites to lure users into downloading executables that would otherwise be detected as suspicious. This vulnerability affects Firefox < 56, Firefox ESR < 52.4, and Thunderbird < 52.4.
Why it matters now
EPSS 0.01191 68th percentileScored 2026-11-07
Fix Fixed Firefox (Mozilla): 56Firefox ESR (Mozilla): 52.4+1 more productRed Hat: 2 advisories
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mozilla | Firefox | before 56 | 56 | Patch available | CNA |
| Mozilla | Firefox ESR | before 52.4 | 52.4 | Patch available | CNA |
| Mozilla | Thunderbird | before 52.4 | 52.4 | Patch available | CNA |
- Firefox VendorMozilla Affected before 56 Fixed in 56 Patch available CNA
- Firefox ESR VendorMozilla Affected before 52.4 Fixed in 52.4 Patch available CNA
- Thunderbird VendorMozilla Affected before 52.4 Fixed in 52.4 Patch available CNA
CPE configurations NVD · 14
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:* | 6.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:* | 6.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:* | 7.4 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_eus:7.4:*:*:*:*:*:*:* | 7.4 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_eus:7.5:*:*:*:*:*:*:* | 7.5 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:* | 6.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
| cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* | before 52.4.0; before 56.0 | Vulnerable | Mozilla |
- cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:* Versions 6.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:* Versions 6.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:* Versions 7.4 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_eus:7.4:*:*:*:*:*:*:* Versions 7.4 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_eus:7.5:*:*:*:*:*:*:* Versions 7.5 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:* Versions 6.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 52.4.0; before 56.0 Vulnerable ·Mozilla
Show 4 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* | before 52.4.0 | Vulnerable | Mozilla |
| cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 52.4.0 Vulnerable ·Mozilla
- cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
Remediation
- Fix · CNA Firefox (Mozilla) Fixed in 56
- Fix · CNA Firefox ESR (Mozilla) Fixed in 52.4
- Fix · CNA Thunderbird (Mozilla) Fixed in 52.4
Red Hat 2 advisories
- RHSA-2017:2885 Released 2017-10-11 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux Client (v. 7) thunderbird-52.4.0-2.el7_4
- Red Hat Enterprise Linux Desktop (v. 6) thunderbird-52.4.0-2.el6_9
- Red Hat Enterprise Linux Server Optional (v. 6) thunderbird-52.4.0-2.el6_9
- Red Hat Enterprise Linux Server Optional (v. 7) thunderbird-52.4.0-2.el7_4
- Red Hat Enterprise Linux Workstation (v. 6) thunderbird-52.4.0-2.el6_9
- Red Hat Enterprise Linux Workstation (v. 7) thunderbird-52.4.0-2.el7_4
- RHSA-2017:2831 Released 2017-09-28 · Red Hat rating Criticalfirefox security update
- Red Hat Enterprise Linux Client (v. 7) firefox-52.4.0-1.el7_4
- Red Hat Enterprise Linux Client Optional (v. 7) firefox-52.4.0-1.el7_4
- Red Hat Enterprise Linux Desktop (v. 6) firefox-52.4.0-1.el6_9
- Red Hat Enterprise Linux Desktop Optional (v. 6) firefox-52.4.0-1.el6_9
- Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox-52.4.0-1.el6_9
- Red Hat Enterprise Linux Server (v. 6) firefox-52.4.0-1.el6_9
- Red Hat Enterprise Linux Server (v. 7) firefox-52.4.0-1.el7_4
- Red Hat Enterprise Linux Server Optional (v. 6) firefox-52.4.0-1.el6_9, firefox-52.4.0-1.el6_9.ppc
- Red Hat Enterprise Linux Server Optional (v. 7) firefox-52.4.0-1.el7_4, firefox-52.4.0-1.el7_4.ppc
- Red Hat Enterprise Linux Workstation (v. 6) firefox-52.4.0-1.el6_9
- Red Hat Enterprise Linux Workstation (v. 7) firefox-52.4.0-1.el7_4
- Red Hat Enterprise Linux Workstation Optional (v. 6) firefox-52.4.0-1.el6_9
- Red Hat Enterprise Linux Workstation Optional (v. 7) firefox-52.4.0-1.el7_4
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Mozilla Firefox, Firefox ESR, Thunderbird — GLSA-201803-14
21 records Highest priority Priority MEDIUM 13 MEDIUM, 8 LOW
Other records, highest priority first
- TI-2017-05404 Memory corruption in Mozilla ThunderbirdPriority MEDIUM 49
- TI-2017-05403 Memory corruption in Mozilla ThunderbirdPriority MEDIUM 49
- TI-2017-05441 Memory corruption in Mozilla FirefoxPriority MEDIUM 48
- Advisory ·
Mozilla Firefox, Firefox ESR, Thunderbird — DSA-3987
8 records Highest priority Priority MEDIUM 5 MEDIUM, 3 LOW
Other records, highest priority first
- TI-2017-05441 Memory corruption in Mozilla FirefoxPriority MEDIUM 48
- TI-2017-05436 Use after free in Mozilla FirefoxPriority MEDIUM 48
- TI-2017-05435 Use after free in Mozilla FirefoxPriority MEDIUM 48
Show 3 more groups
- Advisory ·
Mozilla Firefox, Firefox ESR, Thunderbird — DSA-4014
8 records Highest priority Priority MEDIUM 5 MEDIUM, 3 LOW
Other records, highest priority first
- TI-2017-05441 Memory corruption in Mozilla FirefoxPriority MEDIUM 48
- TI-2017-05436 Use after free in Mozilla FirefoxPriority MEDIUM 48
- TI-2017-05435 Use after free in Mozilla FirefoxPriority MEDIUM 48
- Advisory ·
Mozilla Firefox, Firefox ESR, Thunderbird — RHSA-2017:2831
7 records Highest priority Priority MEDIUM 5 MEDIUM, 2 LOW
Other records, highest priority first
- TI-2017-05441 Memory corruption in Mozilla FirefoxPriority MEDIUM 48
- TI-2017-05436 Use after free in Mozilla FirefoxPriority MEDIUM 48
- TI-2017-05435 Use after free in Mozilla FirefoxPriority MEDIUM 48
- Advisory ·
Mozilla Firefox, Firefox ESR, Thunderbird — RHSA-2017:2885
7 records Highest priority Priority MEDIUM 5 MEDIUM, 2 LOW
Other records, highest priority first
- TI-2017-05441 Memory corruption in Mozilla FirefoxPriority MEDIUM 48
- TI-2017-05436 Use after free in Mozilla FirefoxPriority MEDIUM 48
- TI-2017-05435 Use after free in Mozilla FirefoxPriority MEDIUM 48
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux Client (v. 7) | Fixed | RHSA-2017:2831, RHSA-2017:2885 |
| Red Hat Enterprise Linux Client Optional (v. 7) | Fixed | RHSA-2017:2831 |
| Red Hat Enterprise Linux Desktop (v. 6) | Fixed | RHSA-2017:2831, RHSA-2017:2885 |
| Red Hat Enterprise Linux Desktop Optional (v. 6) | Fixed | RHSA-2017:2831 |
| Red Hat Enterprise Linux HPC Node Optional (v. 6) | Fixed | RHSA-2017:2831 |
| Red Hat Enterprise Linux Server (v. 6) | Fixed | RHSA-2017:2831 |
| Red Hat Enterprise Linux Server (v. 7) | Fixed | RHSA-2017:2831 |
| Red Hat Enterprise Linux Server Optional (v. 6) | Fixed | RHSA-2017:2831, RHSA-2017:2885 |
| Red Hat Enterprise Linux Server Optional (v. 7) | Fixed | RHSA-2017:2831, RHSA-2017:2885 |
| Red Hat Enterprise Linux Workstation (v. 6) | Fixed | RHSA-2017:2831, RHSA-2017:2885 |
| Red Hat Enterprise Linux Workstation (v. 7) | Fixed | RHSA-2017:2831, RHSA-2017:2885 |
| Red Hat Enterprise Linux Workstation Optional (v. 6) | Fixed | RHSA-2017:2831 |
| Red Hat Enterprise Linux Workstation Optional (v. 7) | Fixed | RHSA-2017:2831 |
Timeline
- 2026-10-02 Threatist record created from CVE-2017-7814
- 2026-10-03 Alias added: GHSA-95j8-9fpj-7wc6
References
Advisory 9
- [debian-lts-announce] 20171101 [SECURITY] [DLA 1153-1] icedove/thunderbird security update
- https://www.mozilla.org/security/advisories/mfsa2017-22/
- RHSA-2017:2831
- RHSA-2017:2885
- https://www.mozilla.org/security/advisories/mfsa2017-21/
- DSA-4014
- https://www.mozilla.org/security/advisories/mfsa2017-23/
- DSA-3987
- GLSA-201803-14
More Mozilla Firefox vulnerabilities
- TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
- TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
- TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
- TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
- TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
- TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
Sources
- CVE-2017-7814 · CVE Program
- CVE-2017-7814 · NVD
- FIRST EPSS
- GHSA-95j8-9fpj-7wc6 · GitHub Advisory Database · CC BY 4.0
- CVE-2017-7814 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences