Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 15.28% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2015
CVE-2015-3456High confidence
Affected product: Improper Restriction of Operations within the Bounds of a Memory Buffer
Unknown · Unknown
7.7HighCVSS 2.0
Within 7 days
Mitigation availableHigh technical severity; 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
- Apply the linked authoritative mitigation while planning the permanent fix.
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Unknown Unknown and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- 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
9 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 | qemu | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:2.3+dfsg-3 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian trixietrixie · source | xen | Vendor fix publishedDebian records a fixed source-package version for this release. | 4.4.0-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | qemu | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:2.3+dfsg-3 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | xen | Vendor fix publishedDebian records a fixed source-package version for this release. | 4.4.0-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | qemu | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:2.3+dfsg-3 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | xen | Vendor fix publishedDebian records a fixed source-package version for this release. | 4.4.0-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | qemu | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:2.3+dfsg-3 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | virtualbox | Vendor fix publishedDebian records a fixed source-package version for this release. | 4.3.28-dfsg-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | xen | Vendor fix publishedDebian records a fixed source-package version for this release. | 4.4.0-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Mitigation available01
What, why and how
The Floppy Disk Controller (FDC) in QEMU, as used in Xen 4.5.x and earlier and KVM, allows local guest users to cause a denial of service (out-of-bounds write and guest crash) or possibly execute arbitrary code via the (1) FD_CMD_READ_ID, (2) FD_CMD_DRIVE_SPECIFICATION_COMMAND, or other unspecified commands, aka VENOM.
What
The Floppy Disk Controller (FDC) in QEMU, as used in Xen 4.5.x and earlier and KVM, allows local guest users to cause a denial of service (out-of-bounds write and guest crash) or possibly execute arbitrary code via the (1) FD_CMD_READ_ID, (2) FD_CMD_DRIVE_SPECIFICATION_COMMAND, or other unspecified commands, aka VENOM.
Why
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
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
The Floppy Disk Controller (FDC) in QEMU, as used in Xen 4.5.x and earlier and KVM, allows local guest users to cause a denial of service (out-of-bounds write and guest crash) or possibly execute arbitrary code via the (1) FD_CMD_READ_ID, (2) FD_CMD_DRIVE_SPECIFICATION_COMMAND, or other unspecified commands, aka VENOM.
Why
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
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 None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 Restriction of Operations within the Bounds of a Memory Buffer → execute code or commands in the affected security context
- Attack surface
- Unspecified
- Privileges required
- Not stated in the selected CVSS metric
- 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-119 ↗
CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer. The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. AV:A/AC:L/Au:S/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. - Mitigation available
- Affected
- n/a
- Action
- #### Venom 가상화 임의코드 취약점 보안업데이트 권고 2015.05.19 개요 Crowdstrike社는 QEMU의 가상머신 플로피 디스크 컨트롤러에서 ‘가상머신을 탈출할 수 있는 취약점’을 발견, 해당 취약점을 VENOM(Virtualized Environment Neglected Operations Manipulation)이라 명명 낮은 버전의 가상머신 사용자는 악성코드 감염에 취약할 수 있으므로 해결방안에 따라 최신버전으로 업데이트 권고 설명 가상머신의 플로피 디스크 컨트롤러에서 발생하는 취약점을 해결하는 추가 보안 업데이트 발표 - 가상 플로피 디스크 컨트롤러의 길이가 지정된 매개 변수 값을 오버플로우 시킴으로써 가상머신을 탈출해 다른 가상머신에서 임의코드를 실행 시킬 수 있는 취약점 (CVE-2015-3456) 영향 받는 소프트웨어 QEMU Xen KVM VirtualBox(Oracle) ※ VMware, Microsoft Hyper-V, Boches hypervisors는 해당 취약점에 영향 받지 않음 해결 방안 영향 받는 소프트웨어의 클라이언트를 사용하고 있는 시스템 관리자는 다음 참고사이트의 내용을 참조하여 보안업데이트 수행 - QEMU[1], Xen Project[2], Red Hat[3], Citrix[4], FireEye[5], Linode[6] - Rackspace[7], Ubuntu[8], Debian[9], Suse[10], DigitalOcean[11], f5[12] - Joyent[13], Liquid Web[14], UpCloud[15], Amazon[16], Oracle[17] - Barracuda Networks[18] 기타 문의사항 한국인터넷진흥원 인터넷침해대응센터: 국번없이 118 [참고사이트] [1] http://git.qemu.org/?p=qemu.git;a=commitdiff;h=e907746266721f305d67bc0718795fedee2e824c [2] http://xenbits.xen.org/xsa/advisory-133.html [3] https://access.redhat.com/articles/1444903 [4] http://support.citrix.com/article/CTX201078 [5] https://www.fireeye.com/content/dam/fireeye-www/support/pdfs/fireeye-venom-vulnerability.pdf [6] https://blog.linode.com/2015/05/13/venom-cve-2015-3456-vulnerability-and-linode/ [7] https://community.rackspace.com/general/f/53/t/5187 [8] http://www.ubuntu.com/usn/usn-2608-1/ [9] https://security-tracker.debian.org/tracker/CVE-2015-3456 [10] https://www.suse.com/support/kb/doc.php?id=7016497 [11] https://www.digitalocean.com/company/blog/update-on-CVE-2015-3456/ [12] https://support.f5.com/kb/en-us/solutions/public/16000/600/sol16620.html [13] https://help.joyent.com/entries/68099220-Security-Advisory-on-Venom-CVE-2015-3456-in-KVM-QEMU [14] http://www.liquidweb.com/kb/information-on-cve-2015-3456-qemu-vulnerability-venom/ [15] http://status.upcloud.com/incidents/tt05z2340wws [16] http://aws.amazon.com/security/security-bulletins/XSA_Security_Advisory_CVE_2015_3456/ [17] http://www.oracle.com/technetwork/topics/security/alert-cve-2015-3456-2542656.html [18] https://community.barracudanetworks.com/forum/index.php?/topic/25582-cve-2015-3456-venom-vulnerability/?p=71567
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 13 May 2015 · Last source change 6 Aug 2024, 05:47 UTC · CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer
CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source FIRST · tracked since 2026-09-01
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2015-3499
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-2015-3499 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2015-3499"}
- Vendor guidanceAuthoritative vendor guidance changed: removed vendor advisory: debian.org/dsa-3259; removed vendor advisory: debian.org/dsa-3262; 24 further removals.CNA ↗
- Before
- vendor advisory: debian.org/dsa-3259 · vendor advisory: debian.org/dsa-3262 · vendor advisory: debian.org/dsa-3274 · 23 more references
- After
- no authoritative guidance recorded
- Public exploit evidencePublic exploit evidence changed from Public exploit reference to No public exploit.CVE.org ↗
- Before
- Public exploit reference
- After
- No public exploit
- SeveritySeverity changed from Unknown to High.NIST NVD ↗
- Before
- Unknown
- After
- High
- CVSS scoreCVSS score changed from not recorded to 7.7 (CVSS 2.0 · NIST NVD · AV:A/AC:L/Au:S/C:C/I:C/A:C).NIST NVD ↗
- Before
- not recorded
- After
- 7.7 (CVSS 2.0 · NIST NVD · AV:A/AC:L/Au:S/C:C/I:C/A:C)
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
- Remediation statusRemediation status changed from Awaiting fix to Mitigation available.KISA KrCERT/CC ↗
- Before
- Awaiting fix
- After
- Mitigation available
CVE published
Remediation guidance 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.