CVE-2010-4221

HIGHCVSS v2 · 10.010.0—
EchelonGraph scoreLOW confidence

This CVE was only ever scored under CVSS v2.0. NVD CVSS v2.0 base 10.0 — v2 rates that HIGH (v2 bands: LOW 0.0–3.9 / MEDIUM 4.0–6.9 / HIGH 7.0–10.0; v2 has no CRITICAL band). Vector AV:N/AC:L/Au:N/C:C/I:C/A:C. CVSS v2 is an older, coarser metric than v3.1/v4.0 (no Scope, no User Interaction, no Attack Requirements), so it is not directly comparable to a v3 or v4 score. NVD has never re-scored this record under v3. EPSS predicts 91.3% exploitation probability in the next 30 days, which is reflected in EG Risk but does not lift the v2 base. Confidence: LOW.

Sources: epss, nvd_v2
Weaponized
10.0EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 91%
  • Public exploit code is available (Metasploit, Exploit-DB (verified), epss top5pct, epss high, public exploit)
CISA-KEV: Not listedEPSS PROB: 91%CVSS v2: 10.0Exploit: Metasploit · Exploit-DB (verified) · epss top5pct · epss high · public exploitExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Multiple stack-based buffer overflows in the pr_netio_telnet_gets function in netio.c in ProFTPD before 1.3.3c allow remote attackers to execute arbitrary code via vectors involving a TELNET IAC escape character to a (1) FTP or (2) FTPS server.

CVSS v2.0 (legacy)
10.0HIGHNVD never assigned a CVSS v3 rating to this CVE
EG Score
10.0(low)
EG Risk
86(Track)
EG Risk 86/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity100% × 45%
Exploitation91% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
91%
EPSS %ILE
100%
KEV
Not listed

Published

November 9, 2010

Last Modified

April 29, 2026

References (26)

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
proftpd-dfsg—1.3.3a-5—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
proftpd-dfsg—1.3.3a-5—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
proftpd-dfsg—1.3.3a-5—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
proftpd-dfsg—1.3.3a-5—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 2× in last 7d / 7× 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. 2026-08-26 14:40 UTCEPSS rescore
  2. 2026-08-24 11:42 UTCOSV refresh
  3. 2026-08-19 16:58 UTCEPSS rescore
  4. 2026-08-18 13:42 UTCEPSS rescore
  5. 2026-08-16 02:09 UTCEPSS rescore
  6. 2026-08-08 07:49 UTCOSV refresh
  7. 2026-08-06 13:41 UTCEPSS rescore
  8. 2026-07-26 13:42 UTCEG score recompute▲ 10.00
  9. 2026-07-23 01:06 UTCGHSA enrichment
  10. 2026-07-23 01:05 UTCGHSA enrichment
  11. 2026-07-23 01:04 UTCGHSA enrichment
  12. 2026-07-23 01:03 UTCGHSA enrichment
  13. 2026-07-23 01:02 UTCGHSA enrichment
  14. 2026-07-23 01:01 UTCGHSA enrichment
  15. 2026-07-23 01:01 UTCGHSA enrichment
  16. 2026-07-23 00:59 UTCGHSA enrichment
  17. 2026-07-23 00:58 UTCGHSA enrichment
  18. 2026-07-23 00:57 UTCGHSA enrichment
  19. 2026-07-23 00:56 UTCGHSA enrichment
  20. 2026-07-23 00:55 UTCGHSA enrichment
  21. 2026-07-23 00:54 UTCGHSA enrichment
  22. 2026-07-23 00:53 UTCGHSA enrichment
  23. 2026-07-23 00:52 UTCGHSA enrichment
  24. 2026-07-23 00:51 UTCGHSA enrichment
  25. 2026-07-23 00:50 UTCGHSA enrichment
Show 50 more
  1. 2026-07-23 00:49 UTCGHSA enrichment
  2. 2026-07-23 00:48 UTCGHSA enrichment
  3. 2026-07-23 00:47 UTCGHSA enrichment
  4. 2026-07-23 00:45 UTCGHSA enrichment
  5. 2026-07-23 00:44 UTCGHSA enrichment
  6. 2026-07-23 00:43 UTCGHSA enrichment
  7. 2026-07-23 00:43 UTCGHSA enrichment
  8. 2026-07-23 00:42 UTCEG score recompute
  9. 2026-07-23 00:41 UTCGHSA enrichment
  10. 2026-07-23 00:39 UTCGHSA enrichment
  11. 2026-07-23 00:39 UTCEG score recompute▼ 9.00
  12. 2026-07-23 00:07 UTCEG score recompute
  13. 2026-07-22 21:46 UTCEG score recompute
  14. 2026-07-22 14:03 UTCEPSS rescore
  15. 2026-07-22 14:03 UTCEPSS rescore
  16. 2026-07-15 16:54 UTCEPSS rescore
  17. 2026-07-15 16:54 UTCEPSS rescore
  18. 2026-07-05 22:59 UTCOSV refresh
  19. 2026-06-30 23:19 UTCEPSS rescore
  20. 2026-06-29 14:02 UTCEPSS rescore
  21. 2026-06-29 14:02 UTCEPSS rescore
  22. 2026-06-28 04:52 UTCEPSS rescore
  23. 2026-06-28 04:52 UTCEPSS rescore
  24. 2026-06-24 14:02 UTCEPSS rescore
  25. 2026-06-24 14:02 UTCEPSS rescore
  26. 2026-06-23 21:30 UTCEPSS rescore
  27. 2026-06-23 21:29 UTCEPSS rescore
  28. 2026-06-17 17:49 UTCEPSS rescore
  29. 2026-06-17 17:49 UTCEPSS rescore
  30. 2026-06-17 10:05 UTCOSV refresh
  31. 2026-06-15 17:44 UTCEPSS rescore
  32. 2026-06-12 23:08 UTCEPSS rescore
  33. 2026-06-12 23:08 UTCEPSS rescore
  34. 2026-06-10 22:14 UTCEPSS rescore
  35. 2026-06-10 13:17 UTCEPSS rescore
  36. 2026-06-08 14:13 UTCEPSS rescore
  37. 2026-06-04 13:09 UTCEPSS rescore
  38. 2026-06-04 13:09 UTCEPSS rescore
  39. 2026-05-29 13:40 UTCEPSS rescore
  40. 2026-05-29 09:46 UTCEG score recompute
  41. 2026-05-29 09:46 UTCGHSA enrichment
  42. 2026-05-28 13:42 UTCEPSS rescore
  43. 2026-05-28 13:42 UTCEPSS rescore
  44. 2026-05-27 22:18 UTCOSV refresh
  45. 2026-05-21 22:39 UTCEPSS rescore
  46. 2026-05-20 22:37 UTCEPSS rescore
  47. 2026-05-20 22:37 UTCEPSS rescore
  48. 2026-05-20 22:37 UTCEPSS rescore
  49. 2026-05-18 21:29 UTCEPSS rescore
  50. 2026-05-18 21:29 UTCEPSS rescore

Publicly available exploits

(6 references)

Working exploit code is in the public domain (2 Metasploit modules) (1 GitHub PoC) (3 Exploit-DB entries). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCM41doror/cve-2010-4221
    First seen Oct 28, 2017

    This exploit was written to study some concepts, enjoy!

    Open source ↗
  • Exploit-DBEDB-16851✓ verified
    First seen Jan 9, 2011

    ProFTPd 1.3.2 rc3 < 1.3.3b (Linux) - Telnet IAC Buffer Overflow (Metasploit)

    Open source ↗
  • Exploit-DBEDB-16878✓ verified
    First seen Dec 2, 2010

    ProFTPd 1.3.2 rc3 < 1.3.3b (FreeBSD) - Telnet IAC Buffer Overflow (Metasploit)

    Open source ↗
  • Exploit-DBEDB-15449✓ verified
    First seen Nov 7, 2010

    ProFTPd IAC 1.3.x - Remote Command Execution

    Open source ↗
  • Metasploitexploit/linux/ftp/proftp_telnet_iac✓ verified
    First seen Nov 1, 2010

    ProFTPD 1.3.2rc3 - 1.3.3b Telnet IAC Buffer Overflow (Linux)

    Open source ↗
  • Metasploitexploit/freebsd/ftp/proftp_telnet_iac✓ verified
    First seen Nov 1, 2010

    ProFTPD 1.3.2rc3 - 1.3.3b Telnet IAC Buffer Overflow (FreeBSD)

    Open source ↗

Related CVEs(same CWE)

Frequently asked(4)

What is CVE-2010-4221?
CVE-2010-4221 is a high vulnerability published on November 9, 2010. Multiple stack-based buffer overflows in the prnetiotelnet_gets function in netio.c in ProFTPD before 1.3.3c allow remote attackers to execute arbitrary code via vectors involving a TELNET IAC escape character to a (1) FTP or (2) FTPS server.
When was CVE-2010-4221 disclosed?
CVE-2010-4221 was first published in the National Vulnerability Database on November 9, 2010, with the most recent update on April 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2010-4221 actively exploited?
CVE-2010-4221 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 91% probability of exploitation in the next 30 days, which ranks it in the top 0.2% of all scored CVEs.
How do I remediate CVE-2010-4221?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2010-4221, 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.

Dependency Blast Radius

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