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
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.
- Published
- Dec 24, 2011
- Updated
- Jun 16, 2026
- EPSS
- 95.0% · 100th percentile
- CWE
- CWE-120
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Report tools
Action score
68
This week
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- CVSS
- 40 / 40 · 10.0 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 28 / 30 · 95.0%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| mit | krb5-appl | cpe:2.3:a:mit:krb5-appl |
| gnu | inetutils | cpe:2.3:a:gnu:inetutils |
| heimdal project | heimdal | cpe:2.3:a:heimdal_project:heimdal |
| freebsd | freebsd | cpe:2.3:o:freebsd:freebsd |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| opensuse | opensuse | cpe:2.3:o:opensuse:opensuse |
| suse | linux enterprise desktop | cpe:2.3:o:suse:linux_enterprise_desktop |
| suse | linux enterprise server | cpe:2.3:o:suse:linux_enterprise_server |
| suse | linux enterprise software development kit | cpe:2.3:o:suse:linux_enterprise_software_development_kit |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- debian debian linux5.0
- debian debian linux6.0
- debian debian linux7.0
- fedoraproject fedora15
- fedoraproject fedora16
- freebsd freebsd7.3 and later · up to 9.0 inclusive
- gnu inetutilsbefore 1.9
- heimdal project heimdalup to 1.5.1 inclusive
- mit krb5-applup to 1.0.2 inclusive
- opensuse opensuse11.3
- opensuse opensuse11.4
- suse linux enterprise desktop10
- suse linux enterprise desktop11
- suse linux enterprise server10
- suse linux enterprise server11
- suse linux enterprise server9
- suse linux enterprise software development kit10
- suse linux enterprise software development kit11
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | heimdal | before 1.5.dfsg.1-1 | 1.5.dfsg.1-1 |
| Debian:12 | inetutils | before 2:1.8-6 | 2:1.8-6 |
| Debian:12 | krb5 | before 1.8+dfsg~aa+r23527-1 | 1.8+dfsg~aa+r23527-1 |
| Debian:5.0 | heimdal | before 1.2.dfsg.1-2.1+lenny1 | 1.2.dfsg.1-2.1+lenny1 |
| Debian:5.0 | inetutils | before 2:1.5.dfsg.1-9+lenny1 | 2:1.5.dfsg.1-9+lenny1 |
| Debian:5.0 | krb5 | before 1.6.dfsg.4~beta1-5lenny7 | 1.6.dfsg.4~beta1-5lenny7 |
| Debian:6.0 | heimdal | before 1.4.0~git20100726.dfsg.1-2+squeeze1 | 1.4.0~git20100726.dfsg.1-2+squeeze1 |
| Debian:6.0 | inetutils | before 2:1.6-3.1+squeeze1 | 2:1.6-3.1+squeeze1 |
| Debian:6.0 | krb5-appl | before 1:1.0.1-1.2 | 1:1.0.1-1.2 |
| Red Hat:enterprise_linux:4::as | krb5 | before 0:1.3.4-65.el4 | 0:1.3.4-65.el4 |
| Red Hat:enterprise_linux:4::as | krb5-debuginfo | before 0:1.3.4-65.el4 | 0:1.3.4-65.el4 |
| Red Hat:enterprise_linux:4::as | krb5-devel | before 0:1.3.4-65.el4 | 0:1.3.4-65.el4 |
| Red Hat:enterprise_linux:4::as | krb5-libs | before 0:1.3.4-65.el4 | 0:1.3.4-65.el4 |
| Red Hat:enterprise_linux:4::as | krb5-server | before 0:1.3.4-65.el4 | 0:1.3.4-65.el4 |
| Red Hat:enterprise_linux:4::as | krb5-workstation | before 0:1.3.4-65.el4 | 0:1.3.4-65.el4 |
| Red Hat:enterprise_linux:5::client | krb5 | before 0:1.6.1-63.el5_7 | 0:1.6.1-63.el5_7 |
| Red Hat:enterprise_linux:5::client | krb5-debuginfo | before 0:1.6.1-63.el5_7 | 0:1.6.1-63.el5_7 |
| Red Hat:enterprise_linux:5::client | krb5-libs | before 0:1.6.1-63.el5_7 | 0:1.6.1-63.el5_7 |
| Red Hat:enterprise_linux:5::client | krb5-workstation | before 0:1.6.1-63.el5_7 | 0:1.6.1-63.el5_7 |
| Red Hat:enterprise_linux:5::client_workstation | krb5-devel | before 0:1.6.1-63.el5_7 | 0:1.6.1-63.el5_7 |
| Red Hat:enterprise_linux:5::client_workstation | krb5-server | before 0:1.6.1-63.el5_7 | 0:1.6.1-63.el5_7 |
| Red Hat:enterprise_linux:5::client_workstation | krb5-server-ldap | before 0:1.6.1-63.el5_7 | 0:1.6.1-63.el5_7 |
| Red Hat:enterprise_linux:6::client | krb5-appl | before 0:1.0.1-7.el6_2 | 0:1.0.1-7.el6_2 |
| Red Hat:enterprise_linux:6::client | krb5-appl-clients | before 0:1.0.1-7.el6_2 | 0:1.0.1-7.el6_2 |
+29
Same product
mit: all recordsOther highest-scoring records for the same primary product.
- CVE-2019-25018In the rcp client in MIT krb5-appl through 1.0.3, malicious servers could bypass intended access restrictions via the filename of .30Monitor
- CVE-2011-1526ftpd.c in the GSS-API FTP daemon in MIT Kerberos Version 5 Applications (aka krb5-appl) 1.0.1 and earlier does not check the krb5_setegid re27Monitor
- CVE-2019-25017An issue was discovered in rcp in MIT krb5-appl through 1.0.3.23Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Debian:heimdal | 1.5.dfsg.1-1 · Debian:12 | Package registry (OSV) |
| Debian:inetutils | 2:1.8-6 · Debian:12 | Package registry (OSV) |
| Debian:krb5 | 1.8+dfsg~aa+r23527-1 · Debian:12 | Package registry (OSV) |
| Debian:krb5-appl | 1:1.0.1-1.2 · Debian:6.0 | Package registry (OSV) |
| Red Hat:krb5 | 0:1.3.4-65.el4 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| Red Hat:krb5-appl | 0:1.0.1-7.el6_2 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| Red Hat:krb5-appl-clients | 0:1.0.1-7.el6_2 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| Red Hat:krb5-appl-debuginfo | 0:1.0.1-7.el6_2 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| Red Hat:krb5-appl-servers | 0:1.0.1-7.el6_2 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| Red Hat:krb5-debuginfo | 0:1.3.4-65.el4 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| Red Hat:krb5-devel | 0:1.3.4-65.el4 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| Red Hat:krb5-libs | 0:1.3.4-65.el4 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| Red Hat:krb5-server | 0:1.3.4-65.el4 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| Red Hat:krb5-server-ldap | 0:1.6.1-63.el5_7 · Red Hat:enterprise_linux:5::client_workstation | Package registry (OSV) |
| Red Hat:krb5-workstation | 0:1.3.4-65.el4 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Evidence
- Metasploit module ×3
- Exploit-DB entry ×3
- Proof-of-concept repository on GitHub ×3
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Exploit-DB entry | remote | 2012-01-14 |
| Exploit-DB entry | remote | 2012-01-14 |
| Exploit-DB entry | remote | 2011-12-26 |
| Metasploit module | auxiliary/scanner/telnet/telnet_encrypt_overflowTelnet Service Encryption Key ID Overflow Detectionauxiliary | — |
| Metasploit module | exploit/freebsd/telnet/telnet_encrypt_keyidFreeBSD Telnet Service Encryption Key ID Buffer Overflowexploit | 2011-12-23 |
| Metasploit module | exploit/linux/telnet/telnet_encrypt_keyidLinux BSD-derived Telnet Service Encryption Key ID Buffer Overflowexploit | 2011-12-23 |
| Proof-of-concept repository on GitHub | stars:5 | 2017-02-02 |
| Proof-of-concept repository on GitHub | stars:0 | 2018-11-28 |
| Proof-of-concept repository on GitHub | stars:1 | 2020-02-06 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Metasploit-2 d
- Published
- First PoC+1 d
- TodaySep 29, 2026+5393 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- C · data can be read
- Integrity
- C · data or configuration can be modified
- Availability
- C · the service can be disrupted
- Attack complexity
- Low
- Confidentiality impact
- C
- Integrity impact
- C
- Availability impact
- C
Weakness class (CWE)
CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')CVSS vector
AV:N/AC:L/Au:N/C:C/I:C/A:C
nvd-primary
Root cause
When data is copied, the source length is not compared with the size of the destination buffer. Excess data overwrites adjacent memory.
The bug in code
The whole CWE-120 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
char buf[256];memcpy(buf, pkt->data, pkt->len);Fixed
char buf[256];if (pkt->len > sizeof(buf)) { return -EINVAL;}memcpy(buf, pkt->data, pkt->len);Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Overflow BuffersCAPEC-100likelihood: High · Very High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
- Filter Failure through Buffer OverflowCAPEC-24likelihood: High · High
- MIME ConversionCAPEC-42likelihood: High · High
- Overflow Binary Resource FileCAPEC-44likelihood: High · Very High
- Buffer Overflow via Symbolic LinksCAPEC-45likelihood: High · High
- Overflow Variables and TagsCAPEC-46likelihood: High · High
ATT&CK techniques
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
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References
- archives.neohapsis.com/archives/bugtraq/2011-12/0172.html
- git.savannah.gnu.org/cgit/inetutils.git/commit/?id=665f1e73cdd9b38e2d2e11b8db9958a315935592
- lists.fedoraproject.org/pipermail/package-announce/2012-January/071627.html
- lists.fedoraproject.org/pipermail/package-announce/2012-January/071640.html
- lists.freebsd.org/pipermail/freebsd-security/2011-December/006117.html
- lists.freebsd.org/pipermail/freebsd-security/2011-December/006118.html
- lists.freebsd.org/pipermail/freebsd-security/2011-December/006119.html
- lists.freebsd.org/pipermail/freebsd-security/2011-December/006120.html
- lists.opensuse.org/opensuse-security-announce/2012-01/msg00002.html
- lists.opensuse.org/opensuse-security-announce/2012-01/msg00004.html
- lists.opensuse.org/opensuse-security-announce/2012-01/msg00005.html
- lists.opensuse.org/opensuse-security-announce/2012-01/msg00007.html
- lists.opensuse.org/opensuse-security-announce/2012-01/msg00010.html
- lists.opensuse.org/opensuse-security-announce/2012-01/msg00011.html
- lists.opensuse.org/opensuse-security-announce/2012-01/msg00014.html
- lists.opensuse.org/opensuse-security-announce/2012-01/msg00015.html
- osvdb.org/78020
- secunia.com/advisories/46239
- secunia.com/advisories/47341
- secunia.com/advisories/47348
Vendor advisories and official records. Exploit/PoC links are deliberately left out.