What’s Vulnerable › Vulnerabilities

CVE-2017-17688

• Severity: medium (CVSS 5.9 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 5.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2018-05-16 · updated 2026-06-17

Description

The OpenPGP specification allows a Cipher Feedback Mode (CFB) malleability-gadget attack that can indirectly lead to plaintext exfiltration, aka EFAIL. NOTE: third parties report that this is a problem in applications that mishandle the Modification Detection Code (MDC) feature or accept an obsolete packet type, not a problem in the OpenPGP specification

Affected products

• Apple Mail: all versions
• Bloop Airmail: all versions
• Emclient: all versions
• Flipdogsolutions Maildroid: all versions
• Freron Mailmate: all versions
• Horde Imp: all versions
• Microsoft Outlook: 2007
• Mozilla Thunderbird: all versions
• Postbox-Inc Postbox: all versions
• R2Mail2: all versions
• Roundcube Webmail: all versions

References

• http://flaked.sockpuppet.org/2018/05/16/a-unified-timeline.html
• http://www.securityfocus.com/bid/104162
• http://www.securitytracker.com/id/1040904
• https://efail.de
• https://lists.gnupg.org/pipermail/gnupg-users/2018-May/060334.html
• https://news.ycombinator.com/item?id=17066419
• https://protonmail.com/blog/pgp-vulnerability-efail
• https://twitter.com/matthew_d_green/status/995996706457243648
• https://www.patreon.com/posts/cybersecurity-15-18814817
• https://www.synology.com/support/security/Synology_SA_18_22
• http://flaked.sockpuppet.org/2018/05/16/a-unified-timeline.html
• http://www.securityfocus.com/bid/104162

Get alerted when CVE-2017-17688 or the next vulnerability affects your stack