CVE-2020-8616: BIND does not sufficiently limit the number of fetches performed when processing referrals

Affected versions

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

• debian debian linux10.0
• debian debian linux9.0
• isc bind9.13.0 and later · up to 9.13.7 inclusive
• isc bind9.14.0 and later · up to 9.14.11 inclusive
• isc bind9.15.0 and later · up to 9.15.6 inclusive
• isc bind9.16.0 and later · up to 9.16.2 inclusive
• isc bind9.17.0 and later · up to 9.17.1 inclusive
• isc bind9.0.0 and later · up to 9.11.18 inclusive
• isc bind9.12.0 and later · up to 9.12.4 inclusive
• isc bind9.10.5
• isc bind9.10.7
• isc bind9.11.3
• isc bind9.11.5
• isc bind9.11.6
• isc bind9.11.7
• isc bind9.11.8
• isc bind9.12.4
• isc bind9.9.3

Versions reported by the vendor

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

• ISC BIND9

  • 9.0.0 -> 9.11.18, 9.12.0 -> 9.12.4-P2, 9.14.0 -> 9.14.11, 9.16.0 -> 9.16.2, and releases 9.17.0 -> 9.17.1 of the 9.17 experimental development branch. All releases in the obsolete 9.13 and 9.15 develoaffected

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-2015-5477named in ISC BIND 9.x before 9.9.7-P2 and 9.10.x before 9.10.2-P3 allows remote attackers to cause a denial of service (REQUIRE assertion faKEV
  90Now
• CVE-2020-8617A logic error in code which checks TSIG validity can be used to trigger an assertion failure in tsig.c
  60This week
• CVE-2016-2776buffer.c in named in ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9.11.x before 9.11.0rc3 does not properly construct responses,
  60This week

Published before and after this one in the same product

• ← EarlierCVE-2013-5661Nov 5, 2019 · Cache Poisoning issue exists in DNS Response Rate Limiting.
  24Monitor
• ← EarlierCVE-2019-6477Nov 26, 2019 · TCP-pipelined queries can bypass tcp-clients limit
  31Monitor
• Later →CVE-2020-8618Jun 17, 2020 · A buffer boundary check assertion in rdataset.c can fail incorrectly during zone transfer
  20Monitor

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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.