Qemu: vnc: infinite loop in inflate_buffer() leads to denial of service
Summary
| CVE | CVE-2023-3255 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2023-09-13 17:15:09 UTC |
| Updated | 2026-11-07 12:17:31 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 6.5 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.018910000 probability, percentile 0.797100000 (date 2026-11-08)
Problem Types: CWE-835 | CWE-835 Loop with Unreachable Exit Condition
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | [email protected] | Secondary | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Fedoraproject | Fedora | 38 | All | All | All |
| Application | Qemu | Qemu | All | All | All | All |
| Operating System | Redhat | Enterprise Linux | 8.0 | All | All | All |
| Operating System | Redhat | Enterprise Linux | 9.0 | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Enterprise Linux 8 | unaffected 8100020240314161907.e155f54d * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8 | unaffected 8100020240314161907.e155f54d * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | unaffected 17:8.2.0-11.el9_4 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8 Advanced Virtualization | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| 2218486 – (CVE-2023-3255) CVE-2023-3255 QEMU: VNC: infinite loop in inflate_buffer() leads to denial of service | af854a3a-2127-422b-91ae-364da2661108 | bugzilla.redhat.com | Issue Tracking, Patch, Third Party Advisory |
| September 2023 QEMU Vulnerabilities in NetApp Products | NetApp Product Security | af854a3a-2127-422b-91ae-364da2661108 | security.netapp.com | |
| access.redhat.com/errata/RHSA-2024:2135 | af854a3a-2127-422b-91ae-364da2661108 | access.redhat.com | |
| access.redhat.com/errata/RHSA-2024:2962 | af854a3a-2127-422b-91ae-364da2661108 | access.redhat.com | |
| cve-details | af854a3a-2127-422b-91ae-364da2661108 | access.redhat.com | Third Party Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Red Hat would like to thank Kevin Denis (Synacktiv) for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2023-06-28T00:00:00.000Z | Reported to Red Hat. |
| CNA | 2023-07-04T00:00:00.000Z | Made public. |
Legacy QID Mappings
- 160960 Oracle Enterprise Linux Security Update for kvm_utils3 (ELSA-2023-12855)