// For flags

CVE-2017-7814

Mozilla: Blob and data URLs bypass phishing and malware protection warnings (MFSA 2017-22)

Severity Score

7.8
*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

Las descargas de archivos codificados con elementos URL "blob:" y "data:" omitían las comprobaciones de descarga de archivos normales a pesar de la característica Phishing and Malware Protection y sus listas de bloqueo de páginas y archivos sospechosos. Esto permitiria a los sitios maliciosos engañar a los usuarios para que descarguen ejecutables que, de otra manera, se habrían detectado como sospechosos. Esta vulnerabilidad afecta a las versiones anteriores a la 56 de Firefox, las versiones anteriores a la 52.4 de Firefox ESR y las versiones anteriores a la 52.4 de Thunderbird.

USN-3435-1 fixed vulnerabilities in Firefox. The update caused the Flash plugin to crash in some circumstances. This update fixes the problem. Multiple security issues were discovered in Firefox. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit these to read uninitialized memory, obtain sensitive information, bypass phishing and malware protection, spoof the origin in modal dialogs, conduct cross-site scripting attacks, cause a denial of service via application crash, or execute arbitrary code. Martin Thomson discovered that NSS incorrectly generated handshake hashes. A remote attacker could potentially exploit this to cause a denial of service via application crash, or execute arbitrary code. Multiple security issues were discovered in WebExtensions. If a user were tricked in to installing a specially crafted extension, an attacker could potentially exploit these to download and open non-executable files without interaction, or obtain elevated privileges. Various other issues were also addressed.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2017-04-12 CVE Reserved
  • 2017-09-29 CVE Published
  • 2024-08-05 CVE Updated
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-20: Improper Input Validation
  • CWE-494: Download of Code Without Integrity Check
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Redhat
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Enterprise Linux Desktop
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6.0
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-
Affected
Redhat
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Enterprise Linux Desktop
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7.0
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-
Affected
Redhat
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Enterprise Linux Server
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6.0
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-
Affected
Redhat
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Enterprise Linux Server
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7.0
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-
Affected
Redhat
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Enterprise Linux Server Aus
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7.4
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-
Affected
Redhat
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Enterprise Linux Server Eus
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7.4
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-
Affected
Redhat
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Enterprise Linux Server Eus
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7.5
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-
Affected
Redhat
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Enterprise Linux Workstation
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6.0
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-
Affected
Redhat
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Enterprise Linux Workstation
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7.0
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-
Affected
Mozilla
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Firefox
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< 56.0
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-
Affected
Mozilla
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Firefox Esr
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< 52.4.0
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-
Affected
Mozilla
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Thunderbird
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< 52.4.0
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-
Affected
Debian
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Debian Linux
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7.0
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-
Affected
Debian
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Debian Linux
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8.0
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Affected
Debian
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Debian Linux
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9.0
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-
Affected