CVE intelligence and bounded remediation
CVE-2021-47888 — Textpattern security vulnerability
High
CVSS 8.8
Textpattern versions prior to 4.8.3 contain an authenticated remote code execution vulnerability that allows logged-in users to upload malicious PHP files. Attackers can upload a PHP file with a shell command execution payload and execute arbitrary commands by accessing the uploaded file through a specific URL parameter.
- Severity
- High
- CVSS
- 8.8 (3.1)
- Published
- 2026-01-23
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-434
Affected products
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Matched remediation archetype
Path traversal, unsafe upload, and file handling
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Check exposure
- Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
- Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
- Review canonicalization and containment checks across supported operating systems and storage backends.
Remediate safely
- Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
- Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
- Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.
Authoritative sources
Complete CVE record and remediation plan
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