CVE-2021-22945

CRITICAL
9.1
CVSS Score
Published: September 23, 2021 at 12:00 AM UTC
Updated: October 14, 2026 at 12:17 PM UTC
18 products affected across 8 vendorsmacOSDebian LinuxFedora· also runs on 8 platforms

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Severity
CRITICAL9.1
Exploit prediction
EPSS 7%
SSVC
No known exploit

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*.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

12.0.0 ≤ v < 12.3
Affected range stops below 12.3, so it looks safe — our inference, not a vendor statement
7.73.0 ≤ v ≤ 7.78.0
All versions
All versions
netapp-h300e (same device)
All versions
netapp-h300s (same device)
All versions
netapp-h410s (same device)
All versions
netapp-h500e (same device)

Runs on — not affected

The affected product only carries this flaw when running on these platforms. The platforms themselves are not vulnerable.

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

9.1CRITICALCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-415

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