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CVE Record

CVE-2017-5443: An out-of-bounds write vulnerability while decoding improperly formed BinHex format archives.

An out-of-bounds write vulnerability while decoding improperly formed BinHex format archives. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2017-5443 is a Mozilla memory-safety issue in decoding malformed BinHex archive content. The sources identify affected Thunderbird, Firefox ESR, and Firefox versions. No CVSS score or KEV listing is provided, so urgency depends on whether legacy Mozilla clients remain in use.

Executive priority

Prioritize confirmation rather than emergency response. If affected legacy Mozilla clients exist, update or remove them promptly because memory corruption in user-facing clients can carry meaningful endpoint risk.

Technical view

The flaw is an out-of-bounds write during decoding of improperly formed BinHex format archives. Affected products are Thunderbird before 52.1, Firefox before 53, Firefox ESR before 45.9, and Firefox ESR before 52.1. The supplied sources do not state exploitability details, CVSS, CWE, or active exploitation.

Likely exposure

Exposure is most likely in environments still running 2017-era Mozilla Firefox, Firefox ESR, or Thunderbird builds, including distribution-packaged versions from Red Hat or Debian before the relevant advisory updates.

Exploitation context

The bundle does not cite active exploitation, proof-of-concept use, or CISA KEV inclusion. Treat this as a legacy client-side parsing risk until asset inventory confirms affected versions are absent.

Researcher notes

Available evidence is limited to the CVE description and vendor references. The root condition is malformed BinHex archive decoding causing an out-of-bounds write. Do not assume exploitability, payload requirements, or impact beyond the sourced description without reviewing Mozilla Bugzilla and vendor advisories directly.

Mitigation direction

  • Upgrade Thunderbird to 52.1 or later, or a supported current release.
  • Upgrade Firefox to 53 or later, or a supported current release.
  • Upgrade Firefox ESR to 45.9/52.1 or later, matching the supported ESR track.
  • Apply Red Hat or Debian security updates where Mozilla packages are distribution-managed.
  • Retire unsupported Mozilla browser or mail clients that cannot be updated.

Validation and detection

  • Inventory Firefox, Firefox ESR, and Thunderbird versions across managed endpoints.
  • Confirm no installed version is below Mozilla's fixed version thresholds.
  • Review Red Hat and Debian package advisory status for managed Linux fleets.
  • Check vulnerability scanner results against actual installed package versions.
  • Document any legacy exceptions and compensating controls.
Prepared
Confidence
medium
Sources
9

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.

ATT&CK lookup starting points

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CVE-2017-5443 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 ESRunspecified, unspecifiedListed
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.