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CVE Record

CVE-2020-24661: GNOME Geary before 3.36.3 mishandles pinned TLS certificate verification for IMAP and SMTP services using i...

GNOME Geary before 3.36.3 mishandles pinned TLS certificate verification for IMAP and SMTP services using invalid TLS certificates (e.g., self-signed certificates) when the client system is not configured to use a system-provided PKCS#11 store. This allows a meddler in the middle to present a different invalid certificate to intercept incoming and outgoing mail.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

GNOME Geary before 3.36.3 could fail to protect pinned TLS certificate decisions for IMAP and SMTP when invalid certificates were used and a system PKCS#11 store was not configured. A network-positioned attacker could swap in another invalid certificate and intercept mail traffic.

Executive priority

Treat this as a targeted desktop email confidentiality risk, not an internet-wide emergency. Prioritize remediation for users handling sensitive mail over untrusted networks or connecting to mail servers with self-signed or otherwise invalid TLS certificates.

Technical view

The issue affects Geary's handling of pinned TLS certificate verification for IMAP and SMTP services using invalid certificates, such as self-signed certificates. Under the stated PKCS#11 configuration condition, certificate pinning could be bypassed, enabling meddler-in-the-middle interception of incoming and outgoing email.

Likely exposure

Exposure is most likely on Linux desktops using GNOME Geary versions before 3.36.3 with IMAP or SMTP servers presenting invalid TLS certificates, especially where the client lacks a system-provided PKCS#11 store configuration.

Exploitation context

The sources do not report active exploitation, and CISA KEV status is false. Exploitation requires a network position capable of meddler-in-the-middle traffic interception plus the vulnerable client and certificate configuration conditions.

Researcher notes

Evidence is limited to the CVE description, GNOME issue reference, and Fedora advisories. No CVSS, CWE, exploit maturity, or broad affected-product matrix is provided in the source bundle. The Cisco-labeled reference appears unrelated by title and should not expand scope without corroboration.

Mitigation direction

  • Upgrade GNOME Geary to version 3.36.3 or later.
  • Apply Fedora package updates where Fedora-managed Geary packages are used.
  • Review GNOME Geary upstream guidance for any additional project-specific recommendations.
  • Avoid relying on invalid or self-signed mail server certificates where practical.
  • Ensure client certificate storage configuration matches vendor guidance.

Validation and detection

  • Inventory endpoints using GNOME Geary and record installed versions.
  • Confirm whether any Geary installations are earlier than 3.36.3.
  • Identify IMAP or SMTP accounts using invalid or self-signed TLS certificates.
  • Check whether affected clients use a system-provided PKCS#11 store.
  • Verify package updates from the relevant Linux distribution are installed.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
5Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

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