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CVE-2015-1779· NVD / CVE Program· CNA redhat

The VNC websocket frame decoder in QEMU allows remote attackers to cause a denial of service (memory and CPU consumption) via a large (1) we

The VNC websocket frame decoder in QEMU allows remote attackers to cause a denial of service (memory and CPU consumption) via a large (1) websocket payload or (2) HTTP headers section.

HighCVSS 8.6 · v3.1—No exploit Fix available
Published
Jan 12, 2016
Updated
Jun 16, 2026
EPSS
6.6% · 94th percentile
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Report tools

JSON

Action score

36

Monitor

Low priority for now.

CVSS
34 / 40 · 8.6 / 10
CISA KEV
0 / 30 · Not listed
EPSS
2 / 30 · 6.6%

Affected systems

VendorProduct
qemuqemu
canonicalubuntu linux
debiandebian linux
fedoraprojectfedora
redhatenterprise linux eus
redhatenterprise linux server
redhatenterprise linux server aus
redhatenterprise linux server tus
redhatenterprise linux workstation
redhatvirtualization
redhatenterprise linux
oraclelinux

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • canonical ubuntu linux12.04
  • canonical ubuntu linux14.04
  • canonical ubuntu linux14.10
  • canonical ubuntu linux15.04
  • debian debian linux7.0
  • debian debian linux8.0
  • fedoraproject fedora21
  • fedoraproject fedora22
  • oracle linux7
  • qemu qemuup to 2.2.1 inclusive
  • qemu qemu2.3.0
  • redhat enterprise linux eus7.1
  • redhat enterprise linux eus7.2
  • redhat enterprise linux eus7.3
  • redhat enterprise linux eus7.4
  • redhat enterprise linux eus7.5
  • redhat enterprise linux eus7.6
  • redhat enterprise linux eus7.7
  • redhat enterprise linux server7.0
  • redhat enterprise linux server aus7.3

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12qemubefore 1:2.3+dfsg-11:2.3+dfsg-1
Debian:8qemubefore 1:2.1+dfsg-121:2.1+dfsg-12
Red Hat:enterprise_linux:7::clientlibcacardbefore 10:1.5.3-86.el7_1.810:1.5.3-86.el7_1.8
Red Hat:enterprise_linux:7::clientlibcacard-develbefore 10:1.5.3-86.el7_1.810:1.5.3-86.el7_1.8
Red Hat:enterprise_linux:7::clientlibcacard-toolsbefore 10:1.5.3-86.el7_1.810:1.5.3-86.el7_1.8
Red Hat:enterprise_linux:7::clientqemu-imgbefore 10:1.5.3-86.el7_1.810:1.5.3-86.el7_1.8
Red Hat:enterprise_linux:7::clientqemu-kvmbefore 10:1.5.3-86.el7_1.810:1.5.3-86.el7_1.8
Red Hat:enterprise_linux:7::clientqemu-kvm-commonbefore 10:1.5.3-86.el7_1.810:1.5.3-86.el7_1.8
Red Hat:enterprise_linux:7::clientqemu-kvm-debuginfobefore 10:1.5.3-86.el7_1.810:1.5.3-86.el7_1.8
Red Hat:enterprise_linux:7::clientqemu-kvm-toolsbefore 10:1.5.3-86.el7_1.810:1.5.3-86.el7_1.8
Red Hat:enterprise_linux:7::hypervisorlibcacard-devel-rhevbefore 10:2.1.2-23.el7_1.1010:2.1.2-23.el7_1.10
Red Hat:enterprise_linux:7::hypervisorlibcacard-rhevbefore 10:2.1.2-23.el7_1.1010:2.1.2-23.el7_1.10
Red Hat:enterprise_linux:7::hypervisorlibcacard-tools-rhevbefore 10:2.1.2-23.el7_1.1010:2.1.2-23.el7_1.10
Red Hat:enterprise_linux:7::hypervisorqemu-img-rhevbefore 10:2.1.2-23.el7_1.1010:2.1.2-23.el7_1.10
Red Hat:enterprise_linux:7::hypervisorqemu-kvm-common-rhevbefore 10:2.1.2-23.el7_1.1010:2.1.2-23.el7_1.10
Red Hat:enterprise_linux:7::hypervisorqemu-kvm-rhevbefore 10:2.1.2-23.el7_1.1010:2.1.2-23.el7_1.10
Red Hat:enterprise_linux:7::hypervisorqemu-kvm-rhev-debuginfobefore 10:2.1.2-23.el7_1.1010:2.1.2-23.el7_1.10
Red Hat:enterprise_linux:7::hypervisorqemu-kvm-tools-rhevbefore 10:2.1.2-23.el7_1.1010:2.1.2-23.el7_1.10
SUSE:Linux Enterprise Desktop 12qemubefore 2.0.2-46.12.0.2-46.1
SUSE:Linux Enterprise Desktop 12xenbefore 4.4.4_02-22.19.14.4.4_02-22.19.1
SUSE:Linux Enterprise Desktop 12 SP1xenbefore 4.5.2_06-7.14.5.2_06-7.1
SUSE:Linux Enterprise Point of Sale 11 SP3kvmbefore 1.4.2-53.38.11.4.2-53.38.1
SUSE:Linux Enterprise Server 11 SP4-LTSSkvmbefore 1.4.2-60.34.11.4.2-60.34.1
SUSE:Linux Enterprise Software Development Kit 11 SP4xenbefore 4.4.4_02-32.14.4.4_02-32.1

Same product

qemu: all records

Other 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 achieve
    46Plan
  • 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 expor
    43Plan
  • 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 arbitr
    41Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:qemu1:2.3+dfsg-1 · Debian:12Package registry (OSV)
red hat:libcacard10:1.5.3-86.el7_1.8 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:libcacard-devel-rhev10:2.1.2-23.el7_1.10 · Red Hat:enterprise_linux:7::hypervisorPackage registry (OSV)
red hat:libcacard-rhev10:2.1.2-23.el7_1.10 · Red Hat:enterprise_linux:7::hypervisorPackage registry (OSV)
red hat:libcacard-tools-rhev10:2.1.2-23.el7_1.10 · Red Hat:enterprise_linux:7::hypervisorPackage registry (OSV)
red hat:qemu-img10:1.5.3-86.el7_1.8 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:qemu-img-rhev10:2.1.2-23.el7_1.10 · Red Hat:enterprise_linux:7::hypervisorPackage registry (OSV)
red hat:qemu-kvm10:1.5.3-86.el7_1.8 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:qemu-kvm-common10:1.5.3-86.el7_1.8 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:qemu-kvm-common-rhev10:2.1.2-23.el7_1.10 · Red Hat:enterprise_linux:7::hypervisorPackage registry (OSV)
red hat:qemu-kvm-rhev10:2.1.2-23.el7_1.10 · Red Hat:enterprise_linux:7::hypervisorPackage registry (OSV)
red hat:qemu-kvm-rhev-debuginfo10:2.1.2-23.el7_1.10 · Red Hat:enterprise_linux:7::hypervisorPackage registry (OSV)
red hat:qemu-kvm-tools-rhev10:2.1.2-23.el7_1.10 · Red Hat:enterprise_linux:7::hypervisorPackage registry (OSV)
suse:kvm1.4.2-60.34.1 · SUSE:Linux Enterprise Server 11 SP4-LTSSPackage registry (OSV)
suse:qemu2.0.2-46.1 · SUSE:Linux Enterprise Desktop 12Package registry (OSV)
suse:xen4.5.2_06-7.1 · SUSE:Linux Enterprise Desktop 12 SP1Package registry (OSV)

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.

EPSS, last 120 days-1% in 7 days

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.

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

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.
  • No account or password is required.
  • 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

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality impact
None
Integrity impact
None
Availability impact
High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

nvd-primary

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
function expand(node) {  return node.children.map(expand);}

Fixed

ts
const MAX_DEPTH = 32;function expand(node, depth = 0) {  if (depth > MAX_DEPTH) throw new Error("too deep");  return node.children.map((c) => expand(c, depth + 1));}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

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 help

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

All records