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Full vulnerability report · 2024
CVE-2024-45817High confidence

x86: Deadlock in vlapic_error()

Xen · Xen

7.3HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:High, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 0.54% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Xen Xen and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 30 daysRemediation target: Within 180 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

5 package states
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 releaseSource packageVendor stateFixed versionEvidence
Debian trixietrixie · sourcexenVendor fix publishedDebian records a fixed source-package version for this release.4.19.1-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourcexenVendor fix publishedDebian records a fixed source-package version for this release.4.17.5+23-ga4e5191dc0-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourcexenVendor fix publishedDebian records a fixed source-package version for this release.4.19.1-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourcexenVendor fix publishedDebian records a fixed source-package version for this release.4.19.1-1Debian Security Tracker ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivexenUnder evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Optional official sources

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

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2024-41694

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

In x86's APIC (Advanced Programmable Interrupt Controller) architecture, error conditions are reported in a status register. Furthermore, the OS can opt to receive an interrupt when a new error occurs. It is possible to configure the error interrupt with an illegal vector, which generates an error when an error interrupt is raised. This case causes Xen to recurse through vlapic_error(). The recursion itself is bounded; errors accumulate in the the status register and only generate an interrupt when a new status bit becomes set. However, the lock protecting this state in Xen will try to be taken recursively, and deadlock.

What

In x86's APIC (Advanced Programmable Interrupt Controller) architecture, error conditions are reported in a status register. Furthermore, the OS can opt to receive an interrupt when a new error occurs. It is possible to configure the error interrupt with an illegal vector, which generates an error when an error interrupt is raised. This case causes Xen to recurse through vlapic_error(). The recursion itself is bounded; errors accumulate in the the status register and only generate an interrupt when a new status bit becomes set. However, the lock protecting this state in Xen will try to be taken recursively, and deadlock.

Why

The product generates an error message that includes sensitive information about its environment, users, or associated data.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

In x86's APIC (Advanced Programmable Interrupt Controller) architecture, error conditions are reported in a status register. Furthermore, the OS can opt to receive an interrupt when a new error occurs. It is possible to configure the error interrupt with an illegal vector, which generates an error when an error interrupt is raised. This case causes Xen to recurse through vlapic_error(). The recursion itself is bounded; errors accumulate in the the status register and only generate an interrupt when a new status bit becomes set. However, the lock protecting this state in Xen will try to be taken recursively, and deadlock.

Why

The product generates an error message that includes sensitive information about its environment, users, or associated data.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

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
a network path → Generation of Error Message Containing Sensitive Information → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-209 ↗

CWE-209: Generation of Error Message Containing Sensitive Information. The product generates an error message that includes sensitive information about its environment, users, or associated data.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CLowConfidentiality impact: A successful attack can cause a limited loss.ILowIntegrity impact: A successful attack can cause a limited loss.ALowAvailability impact: A successful attack can cause a limited loss.
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.
NetworkUnauthenticatedCWE-209
A

Official authority intelligence

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

BSI · German · WID-SEC-2024-2209XEN, Citrix XenServer und Hypervisor: Schwachstelle ermöglicht Denial of Service

Ein entfernter, authentisierter Angreifer kann eine Schwachstelle in XEN, Citrix XenServer und Citrix Systems Hypervisor ausnutzen, um einen Denial of Service Angriff durchzuführen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20241002Security Bulletin 02 Oct 2024

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 02 Oct 2024, published on 2 October 2024. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0810Vulnérabilité dans Xen

Une vulnérabilité a été découverte dans Xen. Elle permet à un attaquant de provoquer un déni de service à distance.

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0809Multiples vulnérabilités dans les produits Citrix

De multiples vulnérabilités ont été découvertes dans les produits Citrix. Elles permettent à un attaquant de provoquer un déni de service à distance.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2024-029896Xen プロジェクトのXenにおけるエラーメッセージによる情報漏えいに関する脆弱性

x86のAPIC(高度プログラム可能割り込みコントローラ)アーキテクチャでは、エラー条件がステータスレジスタで報告されます。さらに、OSは新しいエラーが発生したときに割り込みを受け取るように設定可能です。エラー割り込みに不正なベクタを設定することができ、エラー割り込みが発生するとエラーが生成されます。この場合、Xenはvlapic_error()を再帰的に呼び出します。この再帰呼び出し自体には制限があります。エラーはステータスレジスタに蓄積され、新しいステータスビットがセットされたときにのみ割り込みが生成されます。しかしながら、Xen内でこの状態を保護するロックが再帰的に取得されようとして、デッドロックが発生します。

Official advisory ↗
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
Xen: consult Xen advisory XSA-462
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.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 25 Sept 2024 · Last source change 20 Nov 2024, 21:33 UTC · CWE-209 · Generation of Error Message Containing Sensitive Information

CVE recordCVE.org · 5.1
CVSS sourceCISA ADP
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2024-41694
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
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.
Free version - for non-commercial use only.CVE-2024-45817 · cve.blacktree.nl