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CVE Record

CVE-2017-5378: Hashed codes of JavaScript objects are shared between pages.

Hashed codes of JavaScript objects are shared between pages. This allows for pointer leaks because an object's address can be discovered through hash codes, and also allows for data leakage of an object's content using these hash codes. This vulnerability affects Thunderbird < 45.7, Firefox ESR < 45.7, and Firefox < 51.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2017-5378 is a Mozilla browser and mail-client flaw where JavaScript object hash values were shared between pages. That could leak memory pointers and some object content across page boundaries. It affects old versions of Firefox, Firefox ESR, and Thunderbird before the fixed releases named by Mozilla.

Executive priority

Treat this as a legacy exposure cleanup item unless affected versions are still present. If old Mozilla clients remain in production, prioritize upgrade because the issue crosses page boundaries and can expose memory-related data.

Technical view

The flaw concerns reuse or exposure of hashed JavaScript object codes across pages. Sources state this can disclose object addresses through hash codes and leak object content. Affected versions are Thunderbird before 45.7, Firefox ESR before 45.7, and Firefox before 51.

Likely exposure

Exposure is most likely in legacy desktop environments, old gold images, unsupported virtual desktops, kiosks, or systems pinned to Firefox, Firefox ESR, or Thunderbird versions older than the fixed releases.

Exploitation context

The provided sources do not show KEV listing, active exploitation, or exploit maturity. Abuse would require JavaScript running in an affected Mozilla context, but the bundle does not provide enough evidence to rate practical exploitability.

Researcher notes

Primary evidence is the CVE description and Mozilla/distribution advisories. No CVSS vector, CWE, KEV status, exploit status, or detailed technical patch notes were included in the bundle. Avoid assuming broader Mozilla products are affected.

Mitigation direction

  • Upgrade Firefox to version 51 or later.
  • Upgrade Firefox ESR to version 45.7 or later.
  • Upgrade Thunderbird to version 45.7 or later.
  • Apply relevant Debian, Gentoo, or Red Hat security updates where applicable.
  • Retire or isolate systems that cannot run supported Mozilla versions.

Validation and detection

  • Inventory installed Firefox, Firefox ESR, and Thunderbird versions.
  • Confirm no Firefox installations are older than version 51.
  • Confirm Firefox ESR and Thunderbird are not older than 45.7.
  • Check Linux package advisories for completed security update installation.
  • Document any unsupported legacy exceptions and compensating controls.
Prepared
Confidence
medium
Sources
10

Public sources used

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

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

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CVE-2017-5378 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
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
10Source links

CVSS and timeline data

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

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
MozillaThunderbirdunspecifiedListed
MozillaFirefox ESRunspecifiedListed
MozillaFirefoxunspecifiedListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.