Qemu: vnc: infinite loop in inflate_buffer() leads to denial of service
A flaw was found in the QEMU built-in VNC server while processing ClientCutText messages. A wrong exit condition may lead to an infinite loop when inflating an attacker controlled zlib buffer in the `inflate_buffer` function. This could allow a remote authenticated client who is able to send a clipboard to the VNC server to trigger a denial of service.
- Published
- Sep 13, 2023
- Updated
- Jun 17, 2026
- EPSS
- 1.9% · 79th percentile
- CWE
- CWE-835
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Report tools
Action score
27
Monitor
Low priority for now.
- CVSS
- 26 / 40 · 6.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 1.9%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 6.5
- CNA · redhat
- 6.5
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| qemu | qemu | cpe:2.3:a:qemu:qemu |
| redhat | enterprise linux | cpe:2.3:o:redhat:enterprise_linux |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- fedoraproject fedora38
- qemu qemuup to 8.0.3 inclusive
- redhat enterprise linux8.0
- redhat enterprise linux9.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.
Red Hat Red Hat Enterprise Linux 6
- all versionsunknown
Red Hat Red Hat Enterprise Linux 7
- all versionsunknown
- all versionsunknown
Red Hat Red Hat Enterprise Linux 8
- 8100020240314161907.e155f54d and laternot affected · rpm
- 8100020240314161907.e155f54d and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8 Advanced Virtualization
- all versionsunknown
Red Hat Red Hat Enterprise Linux 9
- 17:8.2.0-11.el9_4 and laternot affected · rpm
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:9 | qemu-guest-agent | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-img | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-audio-pa | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-block-blkio | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-block-curl | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-block-rbd | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-common | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-core | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-device-display-virtio-gpu | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-device-display-virtio-gpu-ccw | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-device-display-virtio-gpu-pci | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-device-display-virtio-vga | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-device-usb-host | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-device-usb-redirect | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-docs | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-tools | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-ui-egl-headless | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-kvm-ui-opengl | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| AlmaLinux:9 | qemu-pr-helper | before 17:8.2.0-11.el9_4 | 17:8.2.0-11.el9_4 |
| Debian:12 | qemu | before 1:7.2+dfsg-7+deb12u2 | 1:7.2+dfsg-7+deb12u2 |
| Debian:13 | qemu | before 1:8.0.4+dfsg-1 | 1:8.0.4+dfsg-1 |
| openSUSE:Tumbleweed | qemu | before 8.0.3-2.1 | 8.0.3-2.1 |
| Red Hat:enterprise_linux:8::appstream | hivex | before 0:1.3.18-23.module+el8.9.0+18724+20190c23 | 0:1.3.18-23.module+el8.9.0+18724+20190c23 |
+96
Same product
qemu: all recordsOther highest-scoring records for the same primary product.
- CVE-2019-12928The QMP migrate command in QEMU version 4.0.0 and earlier is vulnerable to OS command injection, which allows the remote attacker to achieve46Plan
- CVE-2015-8556Local privilege escalation vulnerability in the Gentoo QEMU package before 2.5.0-r1.44Plan
- CVE-2017-15118A stack-based buffer overflow vulnerability was found in NBD server implementation in qemu before 2.11 allowing a client to request an expor43Plan
- CVE-2022-36648The hardware emulation in the of_dpa_cmd_add_l2_flood of rocker device model in QEMU, as used in 7.0.0 and earlier, allows remote attackers 41Plan
- CVE-2017-16845hw/input/ps2.c in Qemu does not validate 'rptr' and 'count' values during guest migration, leading to out-of-bounds access.41Plan
- CVE-2016-7161Heap-based buffer overflow in the .receive callback of xlnx.xps-ethernetlite in QEMU (aka Quick Emulator) allows attackers to execute arbitr41Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| almalinux:qemu-guest-agent | 17:8.2.0-11.el9_4 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:qemu-img | 17:8.2.0-11.el9_4 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:qemu-kvm | 17:8.2.0-11.el9_4 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:qemu-kvm-audio-pa | 17:8.2.0-11.el9_4 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:qemu-kvm-block-blkio | 17:8.2.0-11.el9_4 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:qemu-kvm-block-curl | 17:8.2.0-11.el9_4 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:qemu-kvm-block-rbd | 17:8.2.0-11.el9_4 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:qemu-kvm-common | 17:8.2.0-11.el9_4 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:qemu-kvm-core | 17:8.2.0-11.el9_4 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:qemu-kvm-device-display-virtio-gpu | 17:8.2.0-11.el9_4 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:qemu-kvm-device-display-virtio-gpu-ccw | 17:8.2.0-11.el9_4 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:qemu-kvm-device-display-virtio-gpu-pci | 17:8.2.0-11.el9_4 · AlmaLinux:9 | Package registry (OSV) |
| debian:qemu | 1:7.2+dfsg-7+deb12u2 · Debian:12 | Package registry (OSV) |
| opensuse:qemu | 7.1.0-150500.49.6.1 · openSUSE:Leap 15.5 | Package registry (OSV) |
| red hat:qemu-guest-agent | 17:8.2.0-11.el9_4 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:qemu-guest-agent-debuginfo | 17:8.2.0-11.el9_4 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:qemu-img | 17:8.2.0-11.el9_4 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:qemu-img-debuginfo | 17:8.2.0-11.el9_4 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:qemu-kvm | 17:8.2.0-11.el9_4 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:qemu-kvm-audio-dbus-debuginfo | 17:8.2.0-11.el9_4 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:qemu-kvm-audio-pa | 17:8.2.0-11.el9_4 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:qemu-kvm-audio-pa-debuginfo | 17:8.2.0-11.el9_4 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:qemu-kvm-block-blkio | 17:8.2.0-11.el9_4 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:qemu-kvm-block-blkio-debuginfo | 17:8.2.0-11.el9_4 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:qemu-kvm-block-curl | 17:8.2.0-11.el9_4 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:qemu-kvm-block-curl-debuginfo | 17:8.2.0-11.el9_4 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| rocky linux:hivex | 0:1.3.18-23.module+el8.10.0+1590+a67ab969 · Rocky Linux:8 | Package registry (OSV) |
| rocky linux:libguestfs | 1:1.44.0-9.module+el8.10.0+1590+a67ab969.rocky · Rocky Linux:8 | Package registry (OSV) |
| rocky linux:libguestfs-winsupport | 0:8.10-1.module+el8.10.0+1451+358d0d76 · Rocky Linux:8 | Package registry (OSV) |
| rocky linux:libiscsi | 0:1.18.0-8.module+el8.10.0+1590+a67ab969 · Rocky Linux:8 | Package registry (OSV) |
+9
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-835 · Loop with Unreachable Exit Condition ('Infinite Loop')CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- access.redhat.com/errata/RHSA-2024:2135
- access.redhat.com/errata/RHSA-2024:2962
- access.redhat.com/security/cve/CVE-2023-3255
- bugzilla.redhat.com/show_bug.cgi?id=2218486
- security.netapp.com/advisory/ntap-20231020-0008/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.