CVE-2011-4862

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 95% 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
Trending — 5 sources updated this weekWeaponized

Also known asEUVD-2011-4779 (ENISA EUVD) · GHSA-x8cr-m6vm-pqh4 (GitHub Security Advisories)Source: ENISA EUVD

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 95%
  • Public exploit code is available (Metasploit, Exploit-DB, marked verified by Exploit-DB, other public proof-of-concept code)
CISA-KEV: Not listedEPSS PROB: 95%CVSS v2: 10.0Exploit: Metasploit · Exploit-DB (verified) · other public PoCExposed 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
83
EG Risk 83/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity100% × 45%
Impact severity (EG Severity): CVSS 10.0 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation95% × 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
95%
EPSS %ILE
99th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (10.0): severity, escalated by confirmed exploitation. This CVE's 10.0 is its impact severity (EG Severity), not escalated.

EG Severity
10.0 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v2.0 · CVSS v2.0AV:N/AC:L/Au:N/C:C/I:C/A:C
EG Likelihood
95% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track* at medium mission impactTrack at low, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

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.

The score's inputs: 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

December 25, 2011

Last Modified

April 29, 2026

References (42)

15 of 42 shown · show the other 27

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)

Data Freshness Timeline

(refreshed 14× in last 7d / 25× 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. 11 repeat rows among the latest 79 are merged into the row they repeat.

  1. 2026-11-01 22:38 UTCEG score recompute
  2. 2026-11-01 22:38 UTCVendor advisory
  3. 2026-11-01 22:38 UTCGHSA enrichmentGHSA-x8cr-m6vm-pqh4 · GitHub severity HIGH
  4. 2026-11-01 20:55 UTCOSV refresh
  5. 2026-10-31 21:15 UTCEG score recompute
  6. 2026-10-31 21:15 UTCVendor advisory
  7. 2026-10-31 21:15 UTCGHSA enrichmentGHSA-x8cr-m6vm-pqh4 · GitHub severity HIGH
  8. 2026-10-30 19:51 UTCEG score recompute
  9. 2026-10-30 19:51 UTCVendor advisory
  10. 2026-10-30 19:51 UTCGHSA enrichmentGHSA-x8cr-m6vm-pqh4 · GitHub severity HIGH
  11. 2026-10-29 18:28 UTCEG score recompute
  12. 2026-10-29 18:28 UTCVendor advisory
  13. 2026-10-29 18:28 UTCGHSA enrichmentGHSA-x8cr-m6vm-pqh4 · GitHub severity HIGH
  14. 2026-10-27 16:26 UTCEPSS rescoreEPSS 95% · 99th percentile
  15. 2026-10-25 20:14 UTCEG score recompute
  16. 2026-10-25 16:26 UTCEPSS rescoreEPSS 95% · 99th percentile
  17. 2026-10-24 21:25 UTCOSV refresh
  18. 2026-10-21 16:26 UTCEPSS rescoreEPSS 95% · 99th percentile
  19. 2026-10-18 11:29 UTCEG score recompute
  20. 2026-10-17 16:26 UTCEPSS rescoreEPSS 95% · 99th percentile
  21. 2026-10-14 16:26 UTCEPSS rescoreEPSS 95% · 99th percentile
  22. 2026-10-12 21:33 UTCEG score recompute
  23. 2026-10-12 16:27 UTCEPSS rescoreEPSS 95% · 99th percentile
  24. 2026-10-12 01:40 UTCEG score recompute
  25. 2026-10-06 15:10 UTCEPSS rescoreEPSS 95% · 99th percentile
Show 43 more
  1. 2026-10-01 02:40 UTCOSV refresh
  2. 2026-09-29 08:24 UTCEG score recompute
  3. 2026-09-26 15:52 UTCEPSS rescoreEPSS 95% · 99th percentile
  4. 2026-09-24 13:57 UTCEPSS rescoreEPSS 95% · 99th percentile
  5. 2026-09-15 03:04 UTCEPSS rescoreEPSS 95% · 99th percentile
  6. 2026-09-12 05:53 UTCOSV refresh
  7. 2026-09-05 15:22 UTCEPSS rescoreEPSS 95% · 99th percentile
  8. 2026-08-28 21:34 UTCEPSS rescoreEPSS 95% · 99th percentile
  9. 2026-08-26 14:40 UTCEPSS rescoreEPSS 95% · 99th percentile
  10. 2026-08-24 11:42 UTCOSV refresh
  11. 2026-08-19 16:59 UTCEPSS rescoreEPSS 95% · 99th percentile
  12. 2026-08-09 13:42 UTCEPSS rescoreEPSS 95% · 99th percentile
  13. 2026-08-08 07:49 UTCOSV refresh
  14. 2026-07-26 13:44 UTCEG score recomputeAssessed again: 10.0 HIGH
  15. 2026-07-23 01:06 UTCVendor advisory
  16. 2026-07-23 01:06 UTCGHSA enrichmentGHSA-x8cr-m6vm-pqh4 · GitHub severity HIGH
  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 rescoreEPSS 95% · 99th percentile
  22. 2026-07-21 15:21 UTCEPSS rescoreEPSS 95% · 99th percentile
  23. 2026-07-18 10:00 UTCEPSS rescoreEPSS 95% · 99th percentile
  24. 2026-07-05 16:59 UTCOSV refresh
  25. 2026-06-27 03:05 UTCEPSS rescoreEPSS 95% · 99th percentile
  26. 2026-06-23 21:30 UTCEPSS rescoreEPSS 95% · 99th percentile
  27. 2026-06-22 14:22 UTCEPSS rescoreEPSS 95% · 99th percentile
  28. 2026-06-21 01:56 UTCEPSS rescoreEPSS 95% · 99th percentile
  29. 2026-06-17 04:14 UTCOSV refresh
  30. 2026-06-15 17:44 UTCEPSS rescoreEPSS 95% · 99th percentile
  31. 2026-06-13 22:57 UTCEPSS rescoreEPSS 92% · 99th percentile
  32. 2026-06-12 23:08 UTCEPSS rescoreEPSS 93% · 99th percentile
  33. 2026-06-06 13:45 UTCEPSS rescoreEPSS 93% · 99th percentile
  34. 2026-06-04 13:09 UTCEPSS rescoreEPSS 93% · 99th percentile
  35. 2026-05-29 13:41 UTCEPSS rescoreEPSS 93% · 99th percentile
  36. 2026-05-29 05:55 UTCEG score recompute
  37. 2026-05-29 05:55 UTCVendor advisory
  38. 2026-05-29 05:55 UTCGHSA enrichmentGHSA-x8cr-m6vm-pqh4 · GitHub severity HIGH
  39. 2026-05-26 13:41 UTCEPSS rescoreEPSS 93% · 99th percentile
  40. 2026-05-24 16:43 UTCEPSS rescoreEPSS 93% · 99th percentile
  41. 2026-05-22 21:15 UTCEPSS rescoreEPSS 93% · 99th percentile
  42. 2026-05-20 22:37 UTCEPSS rescoreEPSS 93% · 99th percentile
  43. 2026-05-18 21:29 UTCEPSS rescoreEPSS 93% · 99th percentile

Publicly available exploits

(7 references)

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

  • Exploit-DBEDB-18368✓ verified
    Published Jan 14, 2012

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

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

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

    Open source ↗
  • Metasploitexploit/freebsd/telnet/telnet_encrypt_keyid✓ verified
    Published Dec 28, 2011

    FreeBSD Telnet Service Encryption Key ID Buffer Overflow

    Open source ↗
  • Metasploitexploit/linux/telnet/telnet_encrypt_keyid✓ verified
    Published Dec 28, 2011

    Linux BSD-derived Telnet Service Encryption Key ID Buffer Overflow

    Open source ↗
  • Metasploitauxiliary/scanner/telnet/telnet_encrypt_overflow✓ verified
    Published Dec 27, 2011

    Telnet Service Encryption Key ID Overflow Detection

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

    TelnetD encrypt_keyid - Function Pointer Overwrite

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

    Go Exploit for CVE-2011-4862

    Open source ↗

Frequently asked(4)

What is CVE-2011-4862?
CVE-2011-4862 is a high-severity vulnerability; its CVE record was 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 made public?
CVE-2011-4862 was made public on December 23, 2011: that is the date its CVE record's CNA, FreeBSD, gives for when the vulnerability was made public. The CVE record itself was published on December 25, 2011. 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-2011-4862 actively exploited?
CVE-2011-4862 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 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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