Security readout for executives and security teams
Plain-English summary
Open vSwitch can be driven into a denial-of-service condition by a specially crafted network packet. The issue affects availability, not confidentiality or data integrity. Systems using the listed Open vSwitch versions should be prioritized for vendor security updates, especially where untrusted traffic reaches the virtual switch.
Executive priority
Treat this as a high-priority availability risk for infrastructure using Open vSwitch. It does not indicate data theft or system takeover, but outage potential justifies prompt patch validation on exposed or multi-tenant systems.
Technical view
CVE-2020-35498 is a CWE-400 resource-consumption flaw in Open vSwitch userspace packet parsing. A crafted packet can cause an overly broad kernel megaflow, potentially exhausting resources and causing denial of service. CVSS 3.1 is 7.5: network-reachable, low complexity, no privileges, no user interaction, availability impact only.
Likely exposure
Exposure is limited to systems running affected Open vSwitch versions listed in the CVE bundle. Risk is higher where untrusted or tenant-controlled traffic can reach Open vSwitch packet processing paths.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. The CVSS vector indicates remote unauthenticated exploitability, but the known impact is denial of service rather than code execution or data compromise.
Researcher notes
The bundle identifies affected Open vSwitch releases through 2.14.2 and describes a userspace parsing issue that can widen kernel megaflows. Fixed versions are not enumerated in the bundle, so remediation should be validated against vendor advisories rather than inferred.
Mitigation direction
- Apply Open vSwitch security updates from the relevant operating system vendor.
- Check Debian, Fedora, Gentoo, or upstream guidance for fixed package availability.
- Reduce exposure of Open vSwitch processing paths to untrusted traffic where feasible.
- Monitor affected hosts for resource exhaustion and availability degradation.
- Prioritize internet-facing or multi-tenant network infrastructure first.
Validation and detection
- Inventory hosts running Open vSwitch and record installed package versions.
- Compare installed versions with affected versions and vendor advisory status.
- Confirm patched packages are installed from the relevant distribution channel.
- Review monitoring for CPU, memory, flow table, or datapath instability.
- Validate service availability after patching in a controlled maintenance window.
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-400: 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-2020-35498 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
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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 vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://bugzilla.redhat.com/show_bug.cgi?id=1908845CVE reference
- https://www.openwall.com/lists/oss-security/2021/02/10/4CVE reference
- DSA-4852CVE reference · vendor-advisory
- [debian-lts-announce] 20210219 [SECURITY] [DLA 2571-1] openvswitch security updateCVE reference · mailing-list
- FEDORA-2021-fba11d37eeCVE reference · vendor-advisory
- GLSA-202311-16CVE reference · vendor-advisory
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.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.