Evidence used
- No CISA KEV confirmation is currently recorded.
- A structured source references public exploit or proof-of-concept material.
- EPSS is 17.11% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2009
CVE-2009-1891High confidence
Affected product: Uncontrolled Resource Consumption
Unknown · Unknown
7.1HighCVSS 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
4 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 | apache2 | Vendor fix publishedDebian records a fixed source-package version for this release. | 2.2.11-7 | Debian Security Tracker ↗Source updated 22 Oct 2026 |
| Debian bookwormbookworm · source | apache2 | Vendor fix publishedDebian records a fixed source-package version for this release. | 2.2.11-7 | Debian Security Tracker ↗Source updated 22 Oct 2026 |
| Debian forkyforky · source | apache2 | Vendor fix publishedDebian records a fixed source-package version for this release. | 2.2.11-7 | Debian Security Tracker ↗Source updated 22 Oct 2026 |
| Debian sidsid · source | apache2 | Vendor fix publishedDebian records a fixed source-package version for this release. | 2.2.11-7 | Debian Security Tracker ↗Source updated 22 Oct 2026 |
Direct vendor intelligence
1 currentAuthoritative vendor CSAF and VEX advisories
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
CVE-2009-1891 · CSAF 2.0 · revision 16 · interimSUSE Product Security TeamCVE-2009-1891
The vendor recommends these product versions as the target state.
- apache2-2.4.33-3.15.1 as component of SUSE Enterprise Storage 6
- apache2-devel-2.4.33-3.15.1 as component of SUSE Enterprise Storage 6
- apache2-doc-2.4.33-3.15.1 as component of SUSE Enterprise Storage 6
- apache2-prefork-2.4.33-3.15.1 as component of SUSE Enterprise Storage 6
- apache2-utils-2.4.33-3.15.1 as component of SUSE Enterprise Storage 6
- apache2-worker-2.4.33-3.15.1 as component of SUSE Enterprise Storage 6
- apache2-2.2.12-1.51.52.1 as component of SUSE Linux Enterprise Desktop 11 SP4
- apache2-devel-2.2.12-1.51.52.1 as component of SUSE Linux Enterprise Desktop 11 SP4
- apache2-doc-2.2.12-1.51.52.1 as component of SUSE Linux Enterprise Desktop 11 SP4
- apache2-example-pages-2.2.12-1.51.52.1 as component of SUSE Linux Enterprise Desktop 11 SP4
- apache2-prefork-2.2.12-1.51.52.1 as component of SUSE Linux Enterprise Desktop 11 SP4
- apache2-utils-2.2.12-1.51.52.1 as component of SUSE Linux Enterprise Desktop 11 SP4
- Summary
- The mod_deflate module in Apache httpd 2.2.11 and earlier compresses large files until completion even after the associated network connection is closed, which allows remote attackers to cause a denial of service (CPU consumption).
- Remediation
- To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
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
The mod_deflate module in Apache httpd 2.2.11 and earlier compresses large files until completion even after the associated network connection is closed, which allows remote attackers to cause a denial of service (CPU consumption).
What
The mod_deflate module in Apache httpd 2.2.11 and earlier compresses large files until completion even after the associated network connection is closed, which allows remote attackers to cause a denial of service (CPU consumption).
Why
The product does not properly control the allocation and maintenance of a limited resource.
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
The mod_deflate module in Apache httpd 2.2.11 and earlier compresses large files until completion even after the associated network connection is closed, which allows remote attackers to cause a denial of service (CPU consumption).
Why
The product does not properly control the allocation and maintenance of a limited resource.
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.
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 → Uncontrolled Resource Consumption → 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
- Not stated in the selected CVSS metric
- Security boundary
- Not stated in the selected CVSS metric
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-400 ↗
CWE-400: Uncontrolled Resource Consumption. The product does not properly control the allocation and maintenance of a limited resource.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. AV:N/AC:M/Au:N/C:N/I:N/A:C- 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.
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
- To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 10 Jul 2009 · Last source change 7 Aug 2024, 05:27 UTC · CWE-400 · Uncontrolled Resource Consumption
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-2009-1886
Product sourceUnavailable
Remediation sourceVendor CSAF · SUSE Product Security Team
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-2009-1886 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2009-1886"}
- Vendor guidanceAuthoritative vendor guidance changed: added patch: bugzilla.redhat.com/show_bug.cgi?id=509125; added patch: mandriva.com/advisories?name=MDVSA-2009:149; removed vendor advisory: debian.org/dsa-1834; removed vendor advisory: lists.apple.com/msg00000.html; 9 further additions; 11 further removals.mandriva.com ↗
- Before
- vendor advisory: debian.org/dsa-1834 · vendor advisory: lists.apple.com/msg00000.html · vendor advisory: lists.opensuse.org/msg00006.html · 10 more references
- After
- patch: bugzilla.redhat.com/show_bug.cgi?id=509125 · patch: mandriva.com/advisories?name=MDVSA-2009:149 · remediation: mandriva.com/advisories?name=MDVSA-2009:149 · 8 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.mandriva.com ↗
- Before
- Awaiting fix
- After
- Patch available
- Public exploit evidencePublic exploit evidence changed from No public exploit to Public exploit reference.marc.info?l=apache-httpd-dev&m=124621326524824&w=2 ↗
- Before
- No public exploit
- After
- Public exploit reference
- SeveritySeverity changed from Unknown to High.NIST NVD ↗
- Before
- Unknown
- After
- High
- CVSS scoreCVSS score changed from not recorded to 7.1 (CVSS 2.0 · NIST NVD · AV:N/AC:M/Au:N/C:N/I:N/A:C).NIST NVD ↗
- Before
- not recorded
- After
- 7.1 (CVSS 2.0 · NIST NVD · AV:N/AC:M/Au:N/C:N/I:N/A:C)
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
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.