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CVE-2011-4862

CriticalExploitedPublic exploit

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…

Published Dec 25, 2011 · Updated Aug 4, 2026 · Also known as DEBIAN-CVE-2011-4862, DSA-2372-1, DSA-2373-1, DSA-2375-1

Key Facts

Patch immediately
  • CVE-2011-4862 is a critical-severity vulnerability (CVSS 10.0 v2) affecting Inetutils (Gnu), Heimdal (Heimdal Project), Krb5-Appl (Mit) and 16 more products.
  • It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Dec 23, 2011. Public exploit code is available.
  • EPSS estimates a 95% probability of exploitation in the next 30 days.
  • Fixed versions are available, including Freebsd 9.0, Inetutils 1.9, Inetutils 2:1.5.dfsg.1-9+lenny1.
  • Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v2

10.0

AV:N/AC:L/Au:N/C:C/I:C/A:C

EPSS (30-day exploit likelihood)

95%

Higher than 99.8% of all scored CVEs

Exploited in the wild

Yes

2 catalog listings

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2011-4862 brief as a PDF

Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.

Description

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.

Known-Exploited Catalog Listings

CatalogAddedRemediation dueRansomware use
Industry KEV feedDec 23, 2011n/aNot reported
CIRCL KEVDec 25, 2011n/aNot reported

Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Affected Products

70 affected entries in total
ProductAffected versionsFixed in
InetutilsGnuSee advisory1.9
HeimdalHeimdal ProjectSee advisory1.5.1
Krb5-ApplMitSee advisory1.0.2
Debian LinuxDebian5.0, 6.0, 7.0n/a
FedoraFedoraproject15, 16n/a
14 more affected products in the full CVE brief

Patched Releases

Freebsd

9.0

Inetutils

1.9, 2:1.5.dfsg.1-9+lenny1, 2:1.6-3.1+squeeze1, 2:1.8-6

Heimdal

1.2.dfsg.1-2.1+lenny1, 1.4.0~git20100726.dfsg.1-2+squeeze1, 1.5.dfsg.1-1, 1.5.1

krb5

0:1.2.7-73, 0:1.3.4-65.el4, 0:1.6.1-63.el5_7, 1.6.dfsg.4~beta1-5lenny7, 1.8+dfsg~aa+r23527-1

Krb5-Appl

0:1.0.1-2.el6_1.3, 1:1.0.1-1.2, 1.0.2

krb5-appl-clients

1.0.1-7.el6_2, 1.0.3-1.1

krb5-appl-servers

1.0.1-7.el6_2, 1.0.3-1.1

krb5-devel

1.6.1-63.el5_7

krb5-libs

1.6.1-63.el5_7

krb5-server

1.6.1-63.el5_7

krb5-server-ldap

1.6.1-63.el5_7

krb5-workstation

1.6.1-63.el5_7

rootio-krb5

1.8+dfsg~aa+r23527-1

Timeline

  1. Added to Industry KEV feed

    Dec 23, 2011

  2. Publicly disclosed

    Dec 25, 2011

  3. Added to CIRCL KEV

    Dec 25, 2011

  4. Last updated

    Aug 4, 2026

Weakness Type

  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
  • CWE-120 Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
  • CWE-130 Improper Handling of Length Parameter Inconsistency
  • CWE-131 Incorrect Calculation of Buffer Size

References

15 more references in the full CVE brief

FAQ

Common Questions.

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