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CVE Record

CVE-2017-5399: Memory safety bugs were reported in Firefox 51.

Memory safety bugs were reported in Firefox 51. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 52 and Thunderbird < 52.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This CVE covers multiple Mozilla memory-safety flaws in Firefox 51. Mozilla stated some showed memory corruption and could potentially be exploited to run arbitrary code. The risk is mainly from old Firefox or Thunderbird installations below version 52, especially systems exposed to web content or email.

Executive priority

Prioritize if legacy Mozilla clients remain in use. For fully modernized environments, this is mostly a historical hygiene issue. The business risk is highest where old browsers or mail clients process untrusted content.

Technical view

CVE-2017-5399 affects Firefox before 52 and Thunderbird before 52. It is an aggregate memory-safety issue from Firefox 51, with evidence of memory corruption. The provided sources do not include CVSS, CWE, exploit details, or confirmed active exploitation.

Likely exposure

Exposure is likely limited to legacy endpoints, VDI images, servers, or lab systems still running Firefox < 52 or Thunderbird < 52.

Exploitation context

The source bundle does not show CISA KEV listing or active exploitation. Mozilla presumed some bugs could be exploitable for arbitrary code execution with enough effort.

Researcher notes

Evidence is incomplete for scoring and exploitation. The CVE aggregates many memory-safety bugs, so validation should focus on affected-version discovery and advisory review, not exploit reproduction.

Mitigation direction

  • Upgrade Firefox and Thunderbird below version 52 to version 52 or a supported current release.
  • Retire legacy Mozilla builds that cannot be updated.
  • Prioritize systems used for web browsing or external email handling.
  • Review Mozilla MFSA advisories for deployment-specific guidance.

Validation and detection

  • Inventory Firefox and Thunderbird versions across endpoints and images.
  • Confirm no production systems run Firefox < 52 or Thunderbird < 52.
  • Check VDI templates, software repositories, and gold images for old Mozilla builds.
  • Document exceptions and compensating controls for unsupported systems.
Prepared
Confidence
medium
Sources
5

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

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ATT&CK lookup starting points

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description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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CVE-2017-5399 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
4Source 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
MozillaFirefoxunspecifiedListed
MozillaThunderbirdunspecifiedListed
Weakness

CWE details

No CWE listed

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