Evidence used
- No CISA KEV confirmation is currently recorded.
- A structured source references public exploit or proof-of-concept material.
- EPSS is 94.98% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2011
CVE-2011-4862High confidence
Affected product: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Unknown · Unknown
10.0HighCVSS 2.0
Within 7 days
Patch availableHigh technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict local access and enforce least privilege on affected hosts.
- Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
- Confirm that the asset runs Unknown Unknown and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Distribution package intelligence
12 package statesRelease-specific package status
Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | heimdal | Vendor fix publishedDebian records a fixed source-package version for this release. | 1.5.dfsg.1-1 | Debian Security Tracker ↗Source updated 4 Oct 2026 |
| Debian trixietrixie · source | inetutils | Vendor fix publishedDebian records a fixed source-package version for this release. | 2:1.8-6 | Debian Security Tracker ↗Source updated 4 Oct 2026 |
| Debian trixietrixie · source | krb5 | Vendor fix publishedDebian records a fixed source-package version for this release. | 1.8+dfsg~aa+r23527-1 | Debian Security Tracker ↗Source updated 4 Oct 2026 |
| Debian bookwormbookworm · source | heimdal | Vendor fix publishedDebian records a fixed source-package version for this release. | 1.5.dfsg.1-1 | Debian Security Tracker ↗Source updated 4 Oct 2026 |
| Debian bookwormbookworm · source | inetutils | Vendor fix publishedDebian records a fixed source-package version for this release. | 2:1.8-6 | Debian Security Tracker ↗Source updated 4 Oct 2026 |
| Debian bookwormbookworm · source | krb5 | Vendor fix publishedDebian records a fixed source-package version for this release. | 1.8+dfsg~aa+r23527-1 | Debian Security Tracker ↗Source updated 4 Oct 2026 |
| Debian forkyforky · source | heimdal | Vendor fix publishedDebian records a fixed source-package version for this release. | 1.5.dfsg.1-1 | Debian Security Tracker ↗Source updated 4 Oct 2026 |
| Debian forkyforky · source | inetutils | Vendor fix publishedDebian records a fixed source-package version for this release. | 2:1.8-6 | Debian Security Tracker ↗Source updated 4 Oct 2026 |
| Debian forkyforky · source | krb5 | Vendor fix publishedDebian records a fixed source-package version for this release. | 1.8+dfsg~aa+r23527-1 | Debian Security Tracker ↗Source updated 4 Oct 2026 |
| Debian sidsid · source | heimdal | Vendor fix publishedDebian records a fixed source-package version for this release. | 1.5.dfsg.1-1 | Debian Security Tracker ↗Source updated 4 Oct 2026 |
| Debian sidsid · source | inetutils | Vendor fix publishedDebian records a fixed source-package version for this release. | 2:1.8-6 | Debian Security Tracker ↗Source updated 4 Oct 2026 |
| Debian sidsid · source | krb5 | Vendor fix publishedDebian records a fixed source-package version for this release. | 1.8+dfsg~aa+r23527-1 | Debian Security Tracker ↗Source updated 4 Oct 2026 |
High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Patch available01
What, why and how
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.
What
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.
Why
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
How
An attacker operating through the affected interface may attempt exploitation when the stated preconditions are met. If successful, the issue may execute code or commands in the affected security context.
What
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.
Why
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
How
An attacker operating through the affected interface may attempt exploitation when the stated preconditions are met. If successful, the issue may execute code or commands in the affected security context.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material Reference recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.
- Likely attack path
- the affected interface → Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') → execute code or commands in the affected security context
- Attack surface
- Unspecified
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- Not stated in the selected CVSS metric
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Not stated in the selected CVSS metric
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-120 ↗
CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow'). The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. AV:N/AC:L/Au:N/C:C/I:C/A:C- Post-exploitation / living off the land
- After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- n/a: n/a
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04
Evidence and provenance
Published 25 Dec 2011 · Last source change 7 Aug 2024, 00:16 UTC · CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source FIRST · tracked since 2026-09-13
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2011-4779
Product sourceUnavailable
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD modified after enrichment
Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.
Material change intelligence
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2011-4779 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2011-4779"}
- Vendor guidanceAuthoritative vendor guidance changed: added mitigation: security.freebsd.org/FreeBSD-SA-11:08.telnetd.asc; added patch: git.savannah.gnu.org/commit?id=665f1e73cdd9b38e2d2e11b8db9958a315935592; removed vendor advisory: debian.org/dsa-2372; removed vendor advisory: debian.org/dsa-2373; 7 further additions; 17 further removals.security.freebsd.org ↗
- Before
- vendor advisory: debian.org/dsa-2372 · vendor advisory: debian.org/dsa-2373 · vendor advisory: debian.org/dsa-2375 · 16 more references
- After
- mitigation: security.freebsd.org/FreeBSD-SA-11:08.telnetd.asc · patch: git.savannah.gnu.org/commit?id=665f1e73cdd9b38e2d2e11b8db9958a315935592 · patch: security.freebsd.org/telnetd.patch · 6 more references
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- n/a: n/a · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- n/a: n/a · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
- Remediation statusRemediation status changed from Awaiting fix to Patch available.security.freebsd.org ↗
- Before
- Awaiting fix
- After
- Patch available
- SeveritySeverity changed from Unknown to High.NIST NVD ↗
- Before
- Unknown
- After
- High
- CVSS scoreCVSS score changed from not recorded to 10.0 (CVSS 2.0 · NIST NVD · AV:N/AC:L/Au:N/C:C/I:C/A:C).NIST NVD ↗
- Before
- not recorded
- After
- 10.0 (CVSS 2.0 · NIST NVD · AV:N/AC:L/Au:N/C:C/I:C/A:C)
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.