CVE-2012-2733: Affected product: Improper Input Validation

Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Fix not verified

What, why and how

java/org/apache/coyote/http11/InternalNioInputBuffer.java in the HTTP NIO connector in Apache Tomcat 6.x before 6.0.36 and 7.x before 7.0.28 does not properly restrict the request-header size, which allows remote attackers to cause a denial of service (memory consumption) via a large amount of header data.

What

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through the affected interface may attempt exploitation when the stated preconditions are met. If successful, the issue may disrupt the affected service.

What

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through the affected interface may attempt exploitation when the stated preconditions are met. If successful, the issue may disrupt the affected service.

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

No confirmed evidence

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

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path: the affected interface → Improper Input Validation → disrupt the affected service
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-20 ↗
CWE-20: Improper Input Validation. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
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:N/I:N/A:P
Post-exploitation / living off the land: No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.

UnauthenticatedDenial of serviceCWE-20

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2012-2713Official EUVD mapping

0 linked advisory records.

Official EUVD record ↗

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.: Fix not verified
Affected: n/a
Fixed: No fixed version is explicitly recorded in the structured CVE data.
Action: No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround: No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.

Evidence and provenance

Published 16 Nov 2012 · Last source change 6 Aug 2024, 19:42 UTC · CWE-20 · Improper Input Validation

CVE recordCVE.org · 5.1

CVSS sourceNIST NVD

EPSS source

The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.

FIRST · tracked since 2026-09-13

European sourceENISA EUVD · EUVD-2012-2713

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

What changed after publication

View recent updates ↗

13 Sep 2026, 17:01 UTC
ENISA EUVD mappingEUVD-2012-2713 was added to the official ENISA EUVD mapping for this CVE.
Before
not recorded
After
{"euvdId":"EUVD-2012-2713"}
ENISA EUVD ↗
6 Aug 2024, 19:42 UTC
Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: tomcat.apache.org/security-6.html; added vendor advisory: tomcat.apache.org/security-7.html; removed vendor advisory: h20566.www2.hp.com/docDisplay?docId=emr_na-c03748878; removed vendor advisory: lists.opensuse.org/msg00037.html; 5 further removals.
Before
vendor advisory: h20566.www2.hp.com/docDisplay?docId=emr_na-c03748878 · vendor advisory: lists.opensuse.org/msg00037.html · vendor advisory: lists.opensuse.org/msg00089.html · 4 more references
After
vendor advisory: tomcat.apache.org/security-6.html · vendor advisory: tomcat.apache.org/security-7.html
tomcat.apache.org ↗
6 Aug 2024, 19:42 UTC
SeveritySeverity changed from Unknown to Medium.
Before
Unknown
After
Medium
NIST NVD ↗
6 Aug 2024, 19:42 UTC
CVSS scoreCVSS score changed from not recorded to 5.0 (CVSS 2.0 · NIST NVD · AV:N/AC:L/Au:N/C:N/I:N/A:P).
Before
not recorded
After
5.0 (CVSS 2.0 · NIST NVD · AV:N/AC:L/Au:N/C:N/I:N/A:P)
NIST NVD ↗
6 Aug 2024, 19:42 UTC
Catalogue recordCVE added to the BlackTree catalogue.
CNA ↗

2012-11-16CVE published

ENISA EUVD · EUVD-2012-2713↗Vendor advisory↗Vendor advisory↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗

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.

Affected product: Improper Input Validation

Published severity in operational context

Evidence used

Compensating controls

Verification

National CERT insights
?
CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

ENISA European Vulnerability Database

EUVD-2012-2713