CVE-2020-27827: A flaw was found in multiple versions of OpenvSwitch.

Affected versions

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

• fedoraproject fedora33
• lldpd project lldpdbefore 1.0.8
• openvswitch openvswitch2.7.0 and later · before 2.7.12
• openvswitch openvswitch2.8.0 and later · before 2.8.10
• openvswitch openvswitch2.9.0 and later · before 2.9.8
• openvswitch openvswitch2.10.0 and later · before 2.10.6
• openvswitch openvswitch2.11.0 and later · before 2.11.5
• openvswitch openvswitch2.12.0 and later · before 2.12.2
• openvswitch openvswitch2.14.0 and later · before 2.14.1
• openvswitch openvswitch2.13.0 and later · before 2.13.2
• openvswitch openvswitch2.6.0 and later · before 2.6.9
• redhat enterprise linux7.0
• redhat enterprise linux8.0
• redhat openshift container platform4.0
• redhat openstack10
• redhat openstack13
• redhat virtualization4.0
• siemens simatic hmi unified comfort panels firmwarebefore 17
• siemens simatic net cp 1243-1 firmwareall versions
• siemens simatic net cp 1243-8 irc firmwareall versions

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

• n/a lldp/openvswitch

  • lldpd 1.0.8, openvswitch 2.14.1, openvswitch 2.13.2, openvswitch 2.12.2, openvswitch 2.11.5, openvswitch 2.10.6, openvswitch 2.9.8, openvswitch 2.8.10, openvswitch 2.7.12, openvswitch 2.6.9affected

Package-level exposure

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

Other highest-scoring records for the same primary product.

• CVE-2016-2074Buffer 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 remote attackers…
  41Plan
• CVE-2017-9265In Open vSwitch (OvS) v2.7.0, there is a buffer over-read while parsing the group mod OpenFlow message sent from the controller in…
  40Plan
• CVE-2017-9264In lib/conntrack.c in the firewall implementation in Open vSwitch (OvS) 2.6.1, there is a buffer over-read while parsing malformed TCP…
  40Plan

Published before and after this one in the same product

• ← EarlierCVE-2018-17206Sep 19, 2018 · An issue was discovered in Open vSwitch (OvS) 2.7.x through 2.7.6.
  20Monitor
• ← EarlierCVE-2020-35498Feb 11, 2021 · A vulnerability was found in openvswitch.
  32Monitor
• Later →CVE-2021-36980Jul 20, 2021 · 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…
  22Monitor

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.

1function expand(node) {2  return node.children.map(expand);3}

1const MAX_DEPTH = 32;2function expand(node, depth = 0) {3  if (depth > MAX_DEPTH) throw new Error("too deep");4  return node.children.map((c) => expand(c, depth + 1));5}

Attack context

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