CVE-2020-12618

Severity: medium (CVSS 4.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-08-20 · updated 2026-06-17

Description

eM Client before 7.2.33412.0 automatically imported S/MIME certificates and thereby silently replaced existing ones. This allowed a man-in-the-middle attacker to obtain an email-validated S/MIME certificate from a trusted CA and replace the public key of the entity to be impersonated. This enabled the attacker to decipher further communication. The entire attack could be accomplished by sending a single email.

Affected products

Emclient Em Client: before 7.2.33412.0 — fixed in 7.2.33412.0

How to fix

Upgrade to a fixed version: Emclient Em Client 7.2.33412.0. Check the vendor advisory for mitigations.

References

https://www.emclient.com/release-history
https://www.nds.ruhr-uni-bochum.de/media/nds/veroeffentlichungen/2020/08/15/mailto-paper.pdf
https://www.emclient.com/release-history
https://www.nds.ruhr-uni-bochum.de/media/nds/veroeffentlichungen/2020/08/15/mailto-paper.pdf

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