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Openvswitch CVE-2021-36980

MEDIUM
Use After Free (CWE-416)
2021-07-20 cve@mitre.org
5.5
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Memory lifecycle management
MITRE ATT&CK

2 techniques across 2 tactics: Execution, Privilege Escalation

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 5.5 (MEDIUM). Attack characteristics: local attack vector, low complexity, no privileges required, user interaction required.

Exploit ScenarioDerived

A local attacker with access to the system could access freed memory to execute arbitrary code or crash the application. No authentication is required to exploit this vulnerability.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 1.2% exploitation probability (EPSS)

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AnalysisAI

Open vSwitch (aka openvswitch) 2.11.0 through 2.15.0 has a use-after-free in decode_NXAST_RAW_ENCAP (called from ofpact_decode and ofpacts_decode) during the decoding of a RAW_ENCAP action. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. This Use After Free vulnerability could allow attackers to access freed memory to execute arbitrary code or crash the application.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Use smart pointers or garbage-collected languages. Set pointers to NULL after freeing. Enable memory sanitizers.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Use After Free (CWE-416), which allows attackers to access freed memory to execute arbitrary code or crash the application. Open vSwitch (aka openvswitch) 2.11.0 through 2.15.0 has a use-after-free in decode_NXAST_RAW_ENCAP (called from ofpact_decode and ofpacts_decode) during the decoding of a RAW_ENCAP action. Affected products include: Openvswitch. Version information: through 2.15.0.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 5.5 MEDIUM
AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

DescriptionNVD

Open vSwitch (aka openvswitch) 2.11.0 through 2.15.0 has a use-after-free in decode_NXAST_RAW_ENCAP (called from ofpact_decode and ofpacts_decode) during the decoding of a RAW_ENCAP action.

Threat Intelligence Overview

EPSS Score
1.2%
Top 36% exploitable
Data Quality
3 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 1.2%
Patch available Yes
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Defer
Exploitation· derived
None
System Exposure· derived
Small
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

29
Low Medium High Critical
KEV: 0
EPSS: +1
CVSS: +28
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Use-after-free vulnerabilities occur when a program continues to access memory through a pointer after that memory has been deallocated.

Memory corruption occurs when a program writes data beyond the boundaries of allocated memory regions or accesses memory in unintended ways, violating the integrity of the process's address space.

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

Affected Products (CPE)NVD

cpe:2.3:a:openvswitch:openvswitch:*:*:*:*:*:*:*:*
CVE-2018-17205 HIGH POC
7.5 Sep 19

An issue was discovered in Open vSwitch (OvS) 2.7.x through 2.7.6, affecting ofproto_rule_insert__ in ofproto/ofproto.c.

CVE-2016-2074 CRITICAL
9.8 Jul 03

Buffer overflow in lib/flow.c in ovs-vswitchd in Open vSwitch 2.2.x and 2.3.x before 2.3.3 and 2.4.x before 2.4.1 allows

CVE-2017-9214 CRITICAL
9.8 May 23

In Open vSwitch (OvS) 2.7.0, while parsing an OFPT_QUEUE_GET_CONFIG_REPLY type OFP 1.0 message, there is a buffer over-r

CVE-2017-9265 CRITICAL
9.8 May 29

In Open vSwitch (OvS) v2.7.0, there is a buffer over-read while parsing the group mod OpenFlow message sent from the con

CVE-2017-9264 CRITICAL
9.8 May 29

In lib/conntrack.c in the firewall implementation in Open vSwitch (OvS) 2.6.1, there is a buffer over-read while parsing

CVE-2016-10377 HIGH
8.8 May 29

In Open vSwitch (OvS) 2.5.0, a malformed IP packet can cause the switch to read past the end of the packet buffer due to

CVE-2026-97612 HIGH
7.8 Sep 25

Linux kernel MPLS handling retains a stale inner_protocol/inner_network_header record after the last MPLS label is poppe

CVE-2026-97611 HIGH
7.8 Sep 25

Use-after-free in the Linux kernel's in-kernel Open vSwitch datapath lets a local user holding CAP_NET_ADMIN crash the k

CVE-2024-22563 HIGH
7.5 Jan 19

openvswitch 2.17.8 was discovered to contain a memory leak via the function xmalloc__ in openvswitch-2.17.8/lib/util.c.

CVE-2017-9263 MEDIUM
6.5 May 29

In Open vSwitch (OvS) 2.7.0, while parsing an OpenFlow role status message, there is a call to the abort() function for

CVE-2022-0669 MEDIUM
6.5 Aug 29

A flaw was found in dpdk. Rated medium severity (CVSS 6.5), this vulnerability is low attack complexity. This Uncontroll

CVE-2017-14970 MEDIUM
5.9 Oct 02

In lib/ofp-util.c in Open vSwitch (OvS) before 2.8.1, there are multiple memory leaks while parsing malformed OpenFlow g

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