CVE-2017-7840: Mozilla Firefox vulnerability

CVE-2017-7840: JavaScript can be injected into an exported bookmarks file by placing JavaScript code into user-supplied ta...

JavaScript can be injected into an exported bookmarks file by placing JavaScript code into user-supplied tags in saved bookmarks. If the resulting exported HTML file is later opened in a browser this JavaScript will be executed. This could be used in social engineering and self-cross-site-scripting (self-XSS) attacks if users were convinced to add malicious tags to bookmarks, export them, and then open the resulting file. This vulnerability affects Firefox < 57.

UnknownCVSS not scoredNot KEV-listedUpdatedAug 5, 2024, 16:19 UTC (UTC+00:00)

Security readout for executives and security teams

Firefox before version 57 could put unsafe JavaScript from bookmark tags into exported bookmark HTML files. The script runs only if that exported file is later opened in a browser. The practical risk depends on social engineering and legacy Firefox use. Exposure is most likely in environments still running Firefox before 57 or retaining old exported bookmark HTML from untrusted workflows. Normal browsing is not described as the trigger. Low priority for modern fleets, but address during legacy browser cleanup. Raise priority if business workflows exchange exported bookmark HTML or still support Firefox before 57. Mitigation focus: Upgrade Firefox installations older than version 57.; Remove or isolate legacy Firefox versions from managed endpoints.; Treat exported bookmark HTML from untrusted sources as unsafe content..

Prepared: Jun 7, 2026, 06:44 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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Vulnerability profileCVE Program record

Severity: Unknown
CVSS: Not scored
Known Exploited: No
Published: Jun 11, 2018, 21:00 UTC (UTC+00:00)

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors

0Timeline events

0ADP providers

3Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

CVE List V5 sourceCVE List V5
https://bugzilla.mozilla.org/show_bug.cgi?id=1366420CVE reference · x_refsource_CONFIRM
https://www.mozilla.org/security/advisories/mfsa2017-24/CVE reference · x_refsource_CONFIRM

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus

MozillaFirefoxunspecifiedListed

Weakness

CWE details

No CWE listed

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