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CVE-2021-3905

25
FAUCET Score

CVE-2021-3905 is a memory leak vulnerability in Open vSwitch (OVS) affecting canonical, fedoraproject, openvswitch, and redhat products, specifically during userspace IP fragmentation processing. With a CVSS score of 7.5 (High), this flaw allows an unauthenticated attacker to remotely exhaust available memory by continuously sending packet fragments, leading to a denial of service. Despite its high severity and potential for impact, there is currently no evidence of active exploitation, publicly available exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
< 2.17.0CPE matchmatch criteria
cpe:2.3:a:openvswitch:openvswitch:*:*:*:*:*:*:*:*
7.0CPE matchmatch criteria
cpe:2.3:a:redhat:enterprise_linux_fast_datapath:7.0:*:*:*:*:*:*:*
8.0CPE matchmatch criteria
cpe:2.3:a:redhat:enterprise_linux_fast_datapath:8.0:*:*:*:*:*:*:*
21.10CPE matchmatch criteria
cpe:2.3:o:canonical:ubuntu_linux:21.10:*:*:*:*:*:*:*
35CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

7.5HIGH

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.58%
Probability of exploitation in next 30 days
EPSS Percentile
72.9%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0158 is in the 55th percentile among its peer group of 51,506 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (12)

github_advisorypatch availablevia nvd_reference
View patch
microsoftpatch availablevia msrc
Product: cm1 openvswitch 2.15.1-2 on CBL Mariner 1.0Fixed in: 2.15.1-2
microsoftpatch availablevia msrc
Product: 18867-16820Fixed in: 2.15.1-2
redhatpatch availablevia nvd_reference
View patch
redhatpatch availablevia redhat_api
Product: Fast Datapath for Red Hat Enterprise Linux 8Fixed in: openvswitch2.16-0:2.16.0-86.el8fdp
View patch
redhatpatch availablevia redhat_api
Product: Fast Datapath for Red Hat Enterprise Linux 8Fixed in: openvswitch2.13-0:2.13.0-139.el8fdp
View patch
redhatpatch availablevia redhat_api
Product: Fast Datapath for Red Hat Enterprise Linux 8Fixed in: openvswitch2.15-0:2.15.0-55.el8fdp
View patch
ubuntupatch availablevia nvd_reference
View patch
redhatend of lifevia redhat_api
Product: Fast Datapath for RHEL 7Fixed in: openvswitch2.13
redhatend of lifevia redhat_api
Product: Red Hat OpenShift Container Platform 4Fixed in: openvswitch2.13
redhatend of lifevia redhat_api
Product: Red Hat OpenShift Container Platform 4Fixed in: openvswitch2.15
redhatend of lifevia redhat_api
Product: Red Hat OpenShift Container Platform 4Fixed in: openvswitch2.16

Vendor Advisories (2)

microsoft2022-Aug/CVE-2021-3905Important

A memory leak was found in Open vSwitch (OVS) during userspace IP fragmentation processing. An attacker could use this flaw to potentially exhaust available memory by keeping sending packet fragments.

Aug 9, 2022
redhatCVE-2021-3905Moderate

openvswitch: External triggered memory leak in Open vSwitch while processing fragmented packets

Sep 29, 2021

References

access.redhat.com / security/cve/CVE-2021-3905
Third Party Advisory
bugzilla.redhat.com / show_bug.cgi
Issue TrackingPatchThird Party Advisory
github.com / openvswitch/ovs/commit/803ed12e31b0377c37d7aa8c94b3b92f2081e349
PatchThird Party Advisory
github.com / openvswitch/ovs-issues/issues/226
ExploitIssue TrackingPatchThird Party Advisory
security.gentoo.org / glsa/202311-16
ubuntu.com / security/CVE-2021-3905
PatchThird Party Advisory