CVE-2011-4862

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 95.0% 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 95%
  • Public exploit code is available (Metasploit, Exploit-DB (verified), epss top5pct, epss high, public exploit)
CISA-KEV: Not listedEPSS PROB: 95%CVSS v2: 10.0Exploit: Metasploit · Exploit-DB (verified) · epss top5pct · epss high · public exploitExposed services: Not assessed

A fix is available — apply it.

Buffer overflow in libtelnet/encrypt.c in telnetd in FreeBSD 7.3 through 9.0, MIT Kerberos Version 5 Applications (aka krb5-appl) 1.0.2 and earlier, Heimdal 1.5.1 and earlier, GNU inetutils, and possibly other products allows remote attackers to execute arbitrary code via a long encryption key, as exploited in the wild in December 2011.

CVSS v2.0 (legacy)
10.0HIGHNVD never assigned a CVSS v3 rating to this CVE
EG Score
10.0HIGHlow confidence
EG Risk
87
EG Risk 87/100CISA SSVC

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%
Exploitation95% × 40%
Automatability30% × 15%
CISA SSVC: Track at low, Track or Track* at medium and Track* or Attend at high mission impact.
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
95%
EPSS %ILE
99th
KEV
Not listed

CISA SSVCTrack at low, Track or Track* at medium and Track* or 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 (EG-KEV: weaponized) · Automatable unknown (not published for this CVE) · Technical impact unknown (not published for this CVE). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

December 25, 2011

Last Modified

April 29, 2026

References (84)

Patch Availability(4)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatkrb5-0:1.6.1-55.el5_6.32011-12-28redhat
redhatkrb5-appl-0:1.0.1-2.el6_1.32011-12-28redhat
redhatkrb5-0:1.6.1-63.el5_72011-12-27redhat
redhatkrb5-appl-0:1.0.1-7.el6_22011-12-27redhat

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.

Affected Packages

(18 across 6 ecosystems)
Debian:11(3)
PackageVulnerable rangeFix by version rangeDependents
heimdal—
  • every version up to 1.5.dfsg.1-1: fixed in 1.5.dfsg.1-1
—
inetutils—
  • every version up to 2:1.8-6: fixed in 2:1.8-6
—
krb5—
  • every version up to 1.8+dfsg~aa+r23527-1: fixed in 1.8+dfsg~aa+r23527-1
—
Debian:12(3)
PackageVulnerable rangeFix by version rangeDependents
heimdal—
  • every version up to 1.5.dfsg.1-1: fixed in 1.5.dfsg.1-1
—
inetutils—
  • every version up to 2:1.8-6: fixed in 2:1.8-6
—
krb5—
  • every version up to 1.8+dfsg~aa+r23527-1: fixed in 1.8+dfsg~aa+r23527-1
—
Debian:13(3)
PackageVulnerable rangeFix by version rangeDependents
heimdal—
  • every version up to 1.5.dfsg.1-1: fixed in 1.5.dfsg.1-1
—
inetutils—
  • every version up to 2:1.8-6: fixed in 2:1.8-6
—
krb5—
  • every version up to 1.8+dfsg~aa+r23527-1: fixed in 1.8+dfsg~aa+r23527-1
—
Debian:14(3)
PackageVulnerable rangeFix by version rangeDependents
heimdal—
  • every version up to 1.5.dfsg.1-1: fixed in 1.5.dfsg.1-1
—
inetutils—
  • every version up to 2:1.8-6: fixed in 2:1.8-6
—
krb5—
  • every version up to 1.8+dfsg~aa+r23527-1: fixed in 1.8+dfsg~aa+r23527-1
—
Debian:5.0(3)
PackageVulnerable rangeFix by version rangeDependents
heimdal1.2.dfsg.1-2.1, 1.2.dfsg.1-2.1+hurd.1
  • every version up to 1.2.dfsg.1-2.1+lenny1: fixed in 1.2.dfsg.1-2.1+lenny1
—
inetutils2:1.5.dfsg.1-9
  • every version up to 2:1.5.dfsg.1-9+lenny1: fixed in 2:1.5.dfsg.1-9+lenny1
—
krb51.6.dfsg.4~beta1-5 ... 1.6.dfsg.4~beta1-5lenny6 (6 versions)
  • every version up to 1.6.dfsg.4~beta1-5lenny7: fixed in 1.6.dfsg.4~beta1-5lenny7
—
Debian:6.0(3)
PackageVulnerable rangeFix by version rangeDependents
heimdal1.4.0~git20100726.dfsg.1-1, 1.4.0~git20100726.dfsg.1-2
  • every version up to 1.4.0~git20100726.dfsg.1-2+squeeze1: fixed in 1.4.0~git20100726.dfsg.1-2+squeeze1
—
inetutils2:1.6-3.1
  • every version up to 2:1.6-3.1+squeeze1: fixed in 2:1.6-3.1+squeeze1
—
krb5-appl1:1.0.1-1, 1:1.0.1-1.1
  • every version up to 1:1.0.1-1.2: fixed in 1:1.0.1-1.2
—

Weakness Classification(1)

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

All Vendor Advisories

(4)

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

Publicly available exploits

(7 references)

Working exploit code is in the public domain (3 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.

  • Exploit-DBEDB-18368✓ verified
    First seen Jan 14, 2012

    Linux BSD-derived Telnet Service Encryption Key ID - Remote Buffer Overflow (Metasploit)

    Open source ↗
  • Exploit-DBEDB-18369✓ verified
    First seen Jan 14, 2012

    FreeBSD - Telnet Service Encryption Key ID Buffer Overflow (Metasploit)

    Open source ↗
  • Exploit-DBEDB-18280✓ verified
    First seen Dec 26, 2011

    TelnetD encrypt_keyid - Function Pointer Overwrite

    Open source ↗
  • Metasploitexploit/freebsd/telnet/telnet_encrypt_keyid✓ verified
    First seen Dec 23, 2011

    FreeBSD Telnet Service Encryption Key ID Buffer Overflow

    Open source ↗
  • Metasploitexploit/linux/telnet/telnet_encrypt_keyid✓ verified
    First seen Dec 23, 2011

    Linux BSD-derived Telnet Service Encryption Key ID Buffer Overflow

    Open source ↗
  • Metasploitauxiliary/scanner/telnet/telnet_encrypt_overflow✓ verified
    First seen Jan 1, 2011

    Telnet Service Encryption Key ID Overflow Detection

    Open source ↗
  • GitHub PoChdbreaker/GO-CVE-2011-4862
    First seen Feb 2, 2017

    Go Exploit for CVE-2011-4862

    Open source ↗

Related CVEs(same product + same CWE)

Frequently asked(4)

What is CVE-2011-4862?
CVE-2011-4862 is a high vulnerability published on December 25, 2011. Buffer overflow in libtelnet/encrypt.c in telnetd in FreeBSD 7.3 through 9.0, MIT Kerberos Version 5 Applications (aka krb5-appl) 1.0.2 and earlier, Heimdal 1.5.1 and earlier, GNU inetutils, and possibly other products allows remote attackers to execute arbitrary code via a long encryption key, as…
When was CVE-2011-4862 disclosed?
CVE-2011-4862 was first published on December 25, 2011, 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-2011-4862 actively exploited?
CVE-2011-4862 is not currently on CISA's Known Exploited Vulnerabilities catalog. EchelonGraph's EG-KEV model classifies it as weaponized: a functional public exploit exists. FIRST EPSS estimates a 95% probability of exploitation in the next 30 days (99th percentile of EPSS-scored CVEs).
How do I remediate CVE-2011-4862?
A fix for CVE-2011-4862 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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