CVE-2009-4018

NONECVSS 0.0Elevated
0.0
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No confirmed exploitation signals yet
CISA-KEV: Not listedEPSS: 11%CVSS: —Exploit: NoneExposed: 0

A fix is available — apply it.

The proc_open function in ext/standard/proc_open.c in PHP before 5.2.11 and 5.3.x before 5.3.1 does not enforce the (1) safe_mode_allowed_env_vars and (2) safe_mode_protected_env_vars directives, which allows context-dependent attackers to execute programs with an arbitrary environment via the env parameter, as demonstrated by a crafted value of the LD_LIBRARY_PATH environment variable.

CVSS v3
—
EG Score
0.0(none)
EPSS
95.5%
KEV
Not listed

Published

November 29, 2009

Last Modified

April 23, 2026

References (32)

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuphp5-cli (5.1.2-1ubuntu3.17) @ dapper2026-05-30ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 5× in last 7d / 37× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-06 16:23 UTCEPSS rescore
  2. 2026-07-05 02:26 UTCEPSS rescore
  3. 2026-07-05 02:26 UTCEPSS rescore
  4. 2026-07-04 06:27 UTCEPSS rescore
  5. 2026-07-01 15:02 UTCEPSS rescore
  6. 2026-06-30 23:19 UTCEPSS rescore
  7. 2026-06-29 14:02 UTCEPSS rescore
  8. 2026-06-29 14:02 UTCEPSS rescore
  9. 2026-06-28 14:03 UTCEPSS rescore
  10. 2026-06-28 04:52 UTCEPSS rescore
  11. 2026-06-28 04:52 UTCEPSS rescore
  12. 2026-06-27 03:05 UTCEPSS rescore
  13. 2026-06-25 13:46 UTCEPSS rescore
  14. 2026-06-25 13:46 UTCEPSS rescore
  15. 2026-06-24 14:02 UTCEPSS rescore
  16. 2026-06-24 14:02 UTCEPSS rescore
  17. 2026-06-23 21:29 UTCEPSS rescore
  18. 2026-06-23 21:29 UTCEPSS rescore
  19. 2026-06-22 14:22 UTCEPSS rescore
  20. 2026-06-22 14:22 UTCEPSS rescore
  21. 2026-06-21 14:53 UTCEPSS rescore
  22. 2026-06-21 01:56 UTCEPSS rescore
  23. 2026-06-21 01:56 UTCEPSS rescore
  24. 2026-06-18 17:49 UTCEPSS rescore
  25. 2026-06-18 17:49 UTCEPSS rescore
Show 45 more
  1. 2026-06-17 17:49 UTCEPSS rescore
  2. 2026-06-17 17:49 UTCEPSS rescore
  3. 2026-06-16 17:49 UTCEPSS rescore
  4. 2026-06-16 17:49 UTCEPSS rescore
  5. 2026-06-15 17:44 UTCEPSS rescore
  6. 2026-06-14 23:14 UTCEPSS rescore
  7. 2026-06-14 23:14 UTCEPSS rescore
  8. 2026-06-13 22:57 UTCEPSS rescore
  9. 2026-06-12 23:08 UTCEPSS rescore
  10. 2026-06-12 23:08 UTCEPSS rescore
  11. 2026-06-10 22:14 UTCEPSS rescore
  12. 2026-06-10 13:17 UTCEPSS rescore
  13. 2026-06-06 13:44 UTCEPSS rescore
  14. 2026-06-06 13:44 UTCEPSS rescore
  15. 2026-06-06 13:44 UTCEPSS rescore
  16. 2026-06-05 22:44 UTCEPSS rescore
  17. 2026-06-05 22:44 UTCEPSS rescore
  18. 2026-06-05 06:07 UTCEPSS rescore
  19. 2026-06-04 13:09 UTCEPSS rescore
  20. 2026-06-04 13:09 UTCEPSS rescore
  21. 2026-06-02 20:10 UTCEPSS rescore
  22. 2026-06-02 20:10 UTCEPSS rescore
  23. 2026-06-01 13:49 UTCEPSS rescore
  24. 2026-06-01 13:49 UTCEPSS rescore
  25. 2026-05-31 00:13 UTCEPSS rescore
  26. 2026-05-31 00:13 UTCEPSS rescore
  27. 2026-05-30 14:31 UTCEG score recompute
  28. 2026-05-30 14:31 UTCVendor advisory
  29. 2026-05-30 14:31 UTCGHSA enrichment
  30. 2026-05-29 13:40 UTCEPSS rescore
  31. 2026-05-28 13:42 UTCEPSS rescore
  32. 2026-05-28 13:42 UTCEPSS rescore
  33. 2026-05-28 13:42 UTCEPSS rescore
  34. 2026-05-27 13:38 UTCEPSS rescore
  35. 2026-05-27 13:38 UTCEPSS rescore
  36. 2026-05-26 07:16 UTCEPSS rescore
  37. 2026-05-26 07:16 UTCEPSS rescore
  38. 2026-05-24 16:43 UTCEPSS rescore
  39. 2026-05-22 21:15 UTCEPSS rescore
  40. 2026-05-22 21:15 UTCEPSS rescore
  41. 2026-05-20 22:37 UTCEPSS rescore
  42. 2026-05-20 22:37 UTCEPSS rescore
  43. 2026-05-20 11:21 UTCEPSS rescore
  44. 2026-05-20 11:20 UTCEPSS rescore
  45. 2026-05-18 21:29 UTCEPSS rescore

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Exploit-DBEDB-11636
    First seen Mar 5, 2010

    Kolang 4.3.10 < 5.3.0 - 'proc_open()' PHP 'safe_mode' Bypass

    Open source ↗

Related CVEs(same vendor)

Frequently asked(4)

What is CVE-2009-4018?
CVE-2009-4018 is a none vulnerability published on November 29, 2009. The procopen function in ext/standard/procopen.c in PHP before 5.2.11 and 5.3.x before 5.3.1 does not enforce the (1) safemodeallowedenvvars and (2) safemodeprotectedenvvars directives, which allows context-dependent attackers to execute programs with an arbitrary environment via the env parameter,…
When was CVE-2009-4018 disclosed?
CVE-2009-4018 was first published in the National Vulnerability Database on November 29, 2009, with the most recent update on April 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2009-4018 actively exploited?
CVE-2009-4018 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 95.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
How do I remediate CVE-2009-4018?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2009-4018, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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