CVE-2021-22945: apple macos Double Free
CVSS: 9.1v3.1CriticalModified
AliasesALPINE-CVE-2021-22945UBUNTU-CVE-2021-22945DEBIAN-CVE-2021-22945
Published 23-09-2021Last modified 14-10-2026
Vulnerability summary
CVE-2021-22945 is a critical (CVSS 9.1) Double Free vulnerability in apple macos. EPSS estimates a 6.68% chance of exploitation in the next 30 days, higher than 93.8% of scored vulnerabilities. 1 public exploit is recorded.
CVSS score
9.1/10
010
Critical · v3.1 (CVE.org)EPSS score
6.68%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference
Advisory lineage
Upstream 0 · Downstream 4 · Related 2Timeline
- 23-09-2021PublishedVulnerability first disclosed.
- 14-10-2026Last modifiedVulnerability information updated.
Description
When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it *again*.
CVSS metrics
6 scores · 5 sources · 2 versionsCritical 9.1Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HSourcesAll 5 agree
- OSV · AlpineEcosystem advisory · calculated9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- OSV · DebianEcosystem advisory · calculated9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- NVDNIST9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Medium 5.8Preferred score · NVD (NIST)
AV:N/AC:M/Au:N/C:P/I:N/A:PSourcesSingle source
EPSS trend
Probability
6.68%
Chance of exploitation in the next 30 days
Percentile
94%
Versus all other CVEs
30-day change
0.00 pp
From 6.68% on 18-09-2026
18-09-202618-10-2026
EPSS score6.68%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundExploit Reference (hackerone.com)
Maturity: unknown
Weaknesses
CWE · root causeAffected systems
Netapp10 products
Debian2 products
- curl< 7.79.1-1
- debian_linuxEOL11.0
Alpine1 product
- curl< 7.79.0-r0
Apple1 product
- macos≥ 12.0.0, < 12.3
Fedoraproject1 product
- fedoraEOL33 | 35
Haxx1 product
- libcurl≥ 7.73.0, ≤ 7.78.0
Oracle1 product
- mysql_server≥ 5.7.0, ≤ 5.7.35 | ≥ 8.0.0, ≤ 8.0.26
Siemens1 product
- sinec_ins< 1.0.1.1
Splunk1 product
- universal_forwarder≥ 8.2.0, < 8.2.12 | ≥ 9.0.0, < 9.0.6 | 9.1.0
Ubuntu1 product
- curl< 7.74.0-1.3ubuntu2
10 vendors · 20 products
References
19 links- security.netapp.com/advisory/ntap-20211029-0003/Third Party Advisory
- support.apple.com/kb/HT213183Third Party Advisory
