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CVE Record

CVE-2010-4657: PHP5 before 5.4.4 allows passing invalid utf-8 strings via the xmlTextWriterWriteAttribute, which are then...

PHP5 before 5.4.4 allows passing invalid utf-8 strings via the xmlTextWriterWriteAttribute, which are then misparsed by libxml2. This results in memory leak into the resulting output.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This issue affects PHP5 versions before 5.4.4. A specially malformed UTF-8 string passed into a PHP XML attribute-writing function can cause memory contents to appear in generated output. The main business concern is unintended information disclosure from legacy PHP systems, but the provided sources do not include severity scoring or evidence of active exploitation.

Executive priority

Prioritize as a legacy exposure review, not an emergency, unless affected PHP5 systems handle sensitive data or expose XML output externally. The absence of severity and exploitation evidence limits urgency, but unsupported legacy runtime presence would raise operational risk.

Technical view

PHP5 before 5.4.4 allows invalid UTF-8 strings through xmlTextWriterWriteAttribute. The data is then misparsed by libxml2, causing memory to leak into the resulting XML output. The bundle names php5 as the affected product and does not provide CVSS, CWE, exploitability detail, or product-specific advisory fixes beyond the version boundary.

Likely exposure

Exposure is most likely in legacy applications still running PHP5 before 5.4.4 and using XMLWriter attribute generation with input that can contain malformed UTF-8. The bundle does not identify affected operating-system packages, distributions, or deployment patterns beyond php5.

Exploitation context

The source bundle does not show KEV listing, public active exploitation, exploit maturity, or exploitation prerequisites. Treat this as a legacy information-disclosure risk until asset inventory proves affected PHP5 versions are absent.

Researcher notes

Evidence is sparse: no CVSS, CWE, KEV status, or detailed advisory text is included. The key technical fact is invalid UTF-8 reaching xmlTextWriterWriteAttribute and libxml2 misparsing that leaks memory into output. Avoid asserting remote exploitability without application-specific data flow evidence.

Mitigation direction

  • Inventory PHP5 runtimes and identify versions before 5.4.4.
  • Check PHP and operating-system vendor guidance for fixed packages.
  • Upgrade or remove affected PHP5 installations where found.
  • Temporarily isolate systems that cannot be upgraded promptly.
  • Review XML output paths that may process untrusted malformed UTF-8.

Validation and detection

  • Confirm whether any production or internal systems run PHP5 before 5.4.4.
  • Identify applications using xmlTextWriterWriteAttribute or XMLWriter attribute generation.
  • Review generated XML exposure for sensitive outputs or public access.
  • Verify remediation against vendor package metadata or PHP version evidence.
Prepared
Confidence
medium
Sources
6

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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CVE-2010-4657 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
5Source 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
php5php5before 5.4.4Listed
Weakness

CWE details

No CWE listed

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