What is CVE-2011-0220?

CVE-2011-0220 is a medium-severity vulnerability in Apple Bonjour, classified under Improper Input Validation. CVSS score: 5.5/10. Published 2020-02-05.

How severe is CVE-2011-0220?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Improper input validation in Apple Bonjour

CVE-2011-0220

Apple Bonjour before 2011 allows a crash via a crafted multicast DNS packet.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2020-02-05 · last modified 2026-06-16.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.003 (15.6th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 15.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Apple Bonjour — versions before 2011

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

opensource.apple.com/source/mDNSResponder/mDNSResponder-541/mDNSPosix/ReadMe.txt (Vendor Advisory)

Frequently asked questions

What is CVE-2011-0220?: CVE-2011-0220 is a medium-severity vulnerability in Apple Bonjour, classified under Improper Input Validation. CVSS score: 5.5/10. Published 2020-02-05.
How severe is CVE-2011-0220?: Medium severity. CVSS v3 base score is 5.5 out of 10.