Security readout for executives and security teams
Plain-English summary
This flaw can let a privileged user inside a virtual machine crash the QEMU process running that VM. The business impact is availability: affected virtual workloads may stop unexpectedly. The sources do not show active exploitation or data theft impact.
Executive priority
Treat as a planned but timely availability fix, higher priority for multi-tenant virtualization or environments where guest administrators are not fully trusted.
Technical view
CVE-2020-35504 is a NULL pointer dereference in QEMU SCSI emulation support before 6.0.0. A privileged guest user can trigger a host-side QEMU process crash, causing denial of service for the affected virtual machine process.
Likely exposure
Exposure is most likely on virtualization hosts or products using QEMU versions before 6.0.0 with SCSI emulation available to guests. Vendor-packaged QEMU may use backported fixes, so version alone may be insufficient.
Exploitation context
The source bundle states exploitation requires a privileged guest user and results in a QEMU process crash. CISA KEV is false, and the provided sources do not claim active exploitation in the wild.
Researcher notes
The provided evidence supports QEMU SCSI emulation, NULL dereference, privileged guest precondition, and denial of service. It does not include CVSS, exploit details, or complete downstream affected-product matrices.
Mitigation direction
- Apply vendor QEMU security updates or move to a fixed release line.
- Prioritize hypervisors hosting untrusted or multi-tenant guest workloads.
- Check Debian, Gentoo, Red Hat, NetApp, and platform vendor guidance.
- Reduce unnecessary guest device exposure where operationally feasible.
Validation and detection
- Inventory systems and products that embed or package QEMU.
- Confirm whether installed QEMU builds include the CVE-2020-35504 fix.
- Identify guest configurations using QEMU SCSI emulation.
- Review host logs for unexplained QEMU process crashes.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-476: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2020-35504 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://bugzilla.redhat.com/show_bug.cgi?id=1909766CVE reference · x_refsource_MISC
- https://www.openwall.com/lists/oss-security/2021/04/16/3CVE reference · x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20210713-0006/CVE reference · x_refsource_CONFIRM
- GLSA-202208-27CVE reference · vendor-advisory, x_refsource_GENTOO
- [debian-lts-announce] 20220905 [SECURITY] [DLA 3099-1] qemu security updateCVE reference · mailing-list, x_refsource_MLIST
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
NULL Pointer Dereference
NULL Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.