CVE-2010-4221

HIGHCVSS v2 · 10.010.0
EchelonGraph scoreLOW confidence

“—” beside the score: it is equal to NVD's CVSS v2 base score.

This CVE was only ever scored under CVSS v2.0. NVD CVSS v2.0 base 10.0 — NVD rates that HIGH (NVD's v2 bands: LOW 0.0–3.9 / MEDIUM 4.0–6.9 / HIGH 7.0–10.0; 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% exploitation probability in the next 30 days; it does not lift the v2 base. EPSS sets EG Risk's exploitation input. Confidence: LOW.

Triggered by: NVD CVSS v2.0 (legacy fallback)
Sources: NVD CVSS v2.0
Weaponized
10.0EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • High exploitation likelihood — EPSS 91%
  • Public exploit code is available (Metasploit, Exploit-DB, marked verified by Exploit-DB, other public proof-of-concept code)
CISA-KEV: Not listedEPSS PROB: 91%CVSS v2: 10.0Exploit: Metasploit · Exploit-DB (verified) · other public PoCExposed services: Not assessed

A fix is available — apply it.

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
10.0HIGHlow confidence
EG Risk
82
EG Risk 82/100

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 (value × EchelonGraph’s weight)
Severity100% × 45%
The EG Score, 10.0 of 10.
Exploitation91% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
91%
EPSS %ILE
99th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

November 9, 2010

Last Modified

April 29, 2026

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
proftpd-dfsg—
  • every version up to 1.3.3a-5: fixed in 1.3.3a-5
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
proftpd-dfsg—
  • every version up to 1.3.3a-5: fixed in 1.3.3a-5
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
proftpd-dfsg—
  • every version up to 1.3.3a-5: fixed in 1.3.3a-5
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
proftpd-dfsg—
  • every version up to 1.3.3a-5: fixed in 1.3.3a-5
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 3× in last 7d / 10× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 13 repeat rows among the latest 90 are merged into the row they repeat.

  1. 2026-10-12 01:46 UTCEG score recompute
  2. 2026-10-09 20:00 UTCEPSS rescoreEPSS 91% · 99th percentile
  3. 2026-10-08 16:33 UTCEPSS rescoreEPSS 91% · 99th percentile
  4. 2026-10-03 14:20 UTCEPSS rescoreEPSS 91% · 99th percentile
  5. 2026-10-01 02:40 UTCOSV refresh
  6. 2026-09-30 14:58 UTCEPSS rescoreEPSS 91% · 99th percentile
  7. 2026-09-29 08:11 UTCEG score recompute
  8. 2026-09-24 13:57 UTCEPSS rescoreEPSS 91% · 99th percentile
  9. 2026-09-20 20:08 UTCEPSS rescoreEPSS 91% · 99th percentile
  10. 2026-09-12 14:54 UTCEPSS rescoreEPSS 91% · 99th percentile
  11. 2026-09-12 05:53 UTCOSV refresh
  12. 2026-09-10 09:24 UTCEPSS rescoreEPSS 91% · 99th percentile
  13. 2026-09-06 13:41 UTCEPSS rescoreEPSS 91% · 99th percentile
  14. 2026-09-05 15:22 UTCEPSS rescoreEPSS 91% · 99th percentile
  15. 2026-08-28 21:34 UTCEPSS rescoreEPSS 91% · 99th percentile
  16. 2026-08-26 14:40 UTCEPSS rescoreEPSS 91% · 99th percentile
  17. 2026-08-24 11:42 UTCOSV refresh
  18. 2026-08-19 16:58 UTCEPSS rescoreEPSS 91% · 99th percentile
  19. 2026-08-18 13:42 UTCEPSS rescoreEPSS 91% · 99th percentile
  20. 2026-08-16 02:09 UTCEPSS rescoreEPSS 91% · 99th percentile
  21. 2026-08-08 07:49 UTCOSV refresh
  22. 2026-08-06 13:41 UTCEPSS rescoreEPSS 91% · 99th percentile
  23. 2026-07-26 13:42 UTCEG score recomputeAssessed again: 10.0 HIGH
  24. 2026-07-23 01:06 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  25. 2026-07-23 01:05 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
Show 52 more
  1. 2026-07-23 01:04 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  2. 2026-07-23 01:03 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  3. 2026-07-23 01:02 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  4. 2026-07-23 01:01 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  5. 2026-07-23 01:01 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  6. 2026-07-23 00:59 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  7. 2026-07-23 00:58 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  8. 2026-07-23 00:57 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  9. 2026-07-23 00:56 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  10. 2026-07-23 00:55 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  11. 2026-07-23 00:54 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  12. 2026-07-23 00:53 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  13. 2026-07-23 00:52 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  14. 2026-07-23 00:51 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  15. 2026-07-23 00:50 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  16. 2026-07-23 00:49 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  17. 2026-07-23 00:48 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  18. 2026-07-23 00:47 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  19. 2026-07-23 00:45 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  20. 2026-07-23 00:44 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  21. 2026-07-23 00:43 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  22. 2026-07-23 00:43 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  23. 2026-07-23 00:42 UTCEG score recompute
  24. 2026-07-23 00:41 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  25. 2026-07-23 00:39 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  26. 2026-07-23 00:39 UTCEG score recompute▼ 9.00
  27. 2026-07-23 00:07 UTCEG score recompute
  28. 2026-07-22 21:46 UTCEG score recompute
  29. 2026-07-22 14:03 UTCEPSS rescoreEPSS 91% · 99th percentile
  30. 2026-07-15 16:54 UTCEPSS rescoreEPSS 91% · 99th percentile
  31. 2026-07-05 22:59 UTCOSV refresh
  32. 2026-06-30 23:19 UTCEPSS rescoreEPSS 91% · 99th percentile
  33. 2026-06-29 14:02 UTCEPSS rescoreEPSS 91% · 99th percentile
  34. 2026-06-28 04:52 UTCEPSS rescoreEPSS 91% · 99th percentile
  35. 2026-06-24 14:02 UTCEPSS rescoreEPSS 91% · 99th percentile
  36. 2026-06-23 21:29 UTCEPSS rescoreEPSS 91% · 99th percentile
  37. 2026-06-17 17:49 UTCEPSS rescoreEPSS 91% · 99th percentile
  38. 2026-06-17 10:05 UTCOSV refresh
  39. 2026-06-15 17:44 UTCEPSS rescoreEPSS 91% · 99th percentile
  40. 2026-06-12 23:08 UTCEPSS rescoreEPSS 92% · 99th percentile
  41. 2026-06-10 22:14 UTCEPSS rescoreEPSS 92% · 99th percentile
  42. 2026-06-10 13:17 UTCEPSS rescoreEPSS 92% · 99th percentile
  43. 2026-06-08 14:13 UTCEPSS rescoreEPSS 92% · 99th percentile
  44. 2026-06-04 13:09 UTCEPSS rescoreEPSS 92% · 99th percentile
  45. 2026-05-29 13:40 UTCEPSS rescoreEPSS 92% · 99th percentile
  46. 2026-05-29 09:46 UTCEG score recompute
  47. 2026-05-29 09:46 UTCGHSA enrichmentGHSA-gf2w-q84f-pmmw · GitHub severity HIGH
  48. 2026-05-28 13:42 UTCEPSS rescoreEPSS 92% · 99th percentile
  49. 2026-05-27 22:18 UTCOSV refresh
  50. 2026-05-21 22:39 UTCEPSS rescoreEPSS 92% · 99th percentile
  51. 2026-05-20 22:37 UTCEPSS rescoreEPSS 92% · 99th percentile
  52. 2026-05-18 21:29 UTCEPSS rescoreEPSS 92% · 99th percentile

Publicly available exploits

(6 references)

Public exploit code is referenced for this CVE (2 Metasploit modules, 3 Exploit-DB entries, 1 GitHub PoC). Defenders should treat patch urgency accordingly.

  • Exploit-DBEDB-16851✓ verified
    Published Jan 9, 2011

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

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

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

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

    ProFTPd IAC 1.3.x - Remote Command Execution

    Open source ↗
  • Metasploitexploit/linux/ftp/proftp_telnet_iac✓ verified
    Published Nov 5, 2010

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

    Open source ↗
  • Metasploitexploit/freebsd/ftp/proftp_telnet_iac✓ verified
    Published Nov 4, 2010

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

    Open source ↗
  • GitHub PoCM41doror/cve-2010-4221
    Published Oct 28, 2017

    This exploit was written to study some concepts, enjoy!

    Open source ↗

Frequently asked(4)

What is CVE-2010-4221?
CVE-2010-4221 is a high-severity vulnerability; its CVE record was 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 made public?
CVE-2010-4221 was made public on October 29, 2010: that is the date its CVE record's CNA, MITRE Corporation, gives for when the vulnerability was made public. The CVE record itself was published on November 9, 2010. EchelonGraph's copy of the record carries a last-modified date of April 29, 2026; the record at its source may have been updated since.
Is CVE-2010-4221 actively exploited?
CVE-2010-4221 is not currently on CISA's Known Exploited Vulnerabilities catalog. EchelonGraph's EG-KEV model places it in Tier 2 (Weaponized), which is not evidence of exploitation: a Metasploit module exists for it, and Exploit-DB marks a public exploit for it as verified. EchelonGraph does not test whether exploit code works. FIRST EPSS estimates a 91% probability of exploitation in the next 30 days (99th percentile of EPSS-scored CVEs).
How do I remediate CVE-2010-4221?
A fix for CVE-2010-4221 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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