CVE-2017-17688
** DISPUTED ** The OpenPGP specification allows a Cipher Feedback Mode (CFB) malleability-gadget...
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
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
5.9
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
- Record
CVE-2017-17688- CVSS 3.0
- 5.9 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:P/I:N/A:N - Updated
- 2026-11-02
CVE List No score
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
- Record
CVE-2017-17688- Updated
- 2026-11-02
EUVDEUVD-2017-8845 No score
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
- Record
EUVD-2017-8845- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-87q6-mg5f-mp98
5.9
** DISPUTED ** The OpenPGP specification allows a Cipher Feedback Mode (CFB) malleability-gadget...
** DISPUTED ** 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.
- Record
GHSA-87q6-mg5f-mp98- CVSS 3.0
- 5.9 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSV
5.9
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
- Record
CVE-2017-17688- CVSS 3.0
- 5.9 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVDEBIAN-CVE-2017-17688
5.9
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
- Record
DEBIAN-CVE-2017-17688- CVSS 3.0
- 5.9 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
Show 4 moreShow less
OSVUBUNTU-CVE-2017-17688
5.9
** DISPUTED ** 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.
- Record
UBUNTU-CVE-2017-17688- CVSS 3.0
- 5.9 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVopenSUSE-SU-2018:1329-1 No score
Security update for enigmail
This update for enigmail to version 2.0.4 fixes multiple issues.
Security issues fixed:
- CVE-2017-17688: CFB gadget attacks allowed to exfiltrate plaintext out of encrypted emails. enigmail now fails on GnuPG integrity check warnings for old Algorithms (bsc#1093151)
- CVE-2017-17689: CBC gadget attacks allows to exfiltrate plaintext out of encrypted emails (bsc#1093152)
This update also includes new and updated functionality:
- The Encryption and Signing buttons now work for both OpenPGP and S/MIME. Enigmail will chose between S/MIME or OpenPGP depending on whether the keys for all recipients are available for the respective standard
- Support for the Autocrypt standard, which is now enabled by default
- Support for Pretty Easy Privacy (p≡p)
- Support for Web Key Directory (WKD)
- The message subject can now be encrypted and replaced with a dummy subject, following the Memory Hole standard forprotected Email Headers
- keys on keyring are automatically refreshed from keyservers at irregular intervals
- Subsequent updates of Enigmail no longer require a restart of Thunderbird
- Keys are internally addressed using the fingerprint instead of the key ID
- Record
openSUSE-SU-2018:1329-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2018:1330-1 No score
Security update for enigmail
This update for enigmail to version 2.0.4 fixes multiple issues.
Security issues fixed:
- CVE-2017-17688: CFB gadget attacks allowed to exfiltrate plaintext out of encrypted emails. enigmail now fails on GnuPG integrity check warnings for old Algorithms (bsc#1093151)
- CVE-2017-17689: CBC gadget attacks allows to exfiltrate plaintext out of encrypted emails (bsc#1093152)
This update also includes new and updated functionality:
- The Encryption and Signing buttons now work for both OpenPGP and S/MIME. Enigmail will chose between S/MIME or OpenPGP depending on whether the keys for all recipients are available for the respective standard
- Support for the Autocrypt standard, which is now enabled by default
- Support for Pretty Easy Privacy (p≡p)
- Support for Web Key Directory (WKD)
- The message subject can now be encrypted and replaced with a dummy subject, following the Memory Hole standard forprotected Email Headers
- keys on keyring are automatically refreshed from keyservers at irregular intervals
- Subsequent updates of Enigmail no longer require a restart of Thunderbird
- Keys are internally addressed using the fingerprint instead of the key ID
- Record
openSUSE-SU-2018:1330-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:10736-1 No score
enigmail-2.2.4-1.4 on GA media
These are all security issues fixed in the enigmail-2.2.4-1.4 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:10736-1- Updated
- 2026-11-02
Affected products
Affected packages
History
| Recorded | Changed | Sources |
|---|---|---|
| affected | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2017-17688 is a medium vulnerability (CVSS 5.9) in Apple Mail, published May 16, 2018. Its validity is disputed. EPSS puts the chance of exploitation in the next 30 days at 5.44%, the 92nd percentile. Fixed in enigmail 2:2.0.6.1-4.
References
protonmail.com/blog/pgp-vulnerability-efail
news.ycombinator.com/item?id=17066419
patreon.com/posts/cybersecurity-15-18814817
flaked.sockpuppet.org/2018/05/16/a-unified-timeline.html
securityfocus.com/bid/104162
lists.gnupg.org/pipermail/gnupg-users/2018-May/060334.html
Show 18 moreShow less
efail.de
twitter.com/matthew_d_green/status/995996706457243648
synology.com/support/security/Synology_SA_18_22
securitytracker.com/id/1040904
nvd.nist.gov/vuln/detail/CVE-2017-17688
github.com/advisories/GHSA-87q6-mg5f-mp98
security-tracker.debian.org/tracker/CVE-2017-17688
ubuntu.com/security/CVE-2017-17688
cve.org/CVERecord?id=CVE-2017-17688
lists.opensuse.org/archives/list/[email protected]/thread/RNZBPQATLVKCT7P5YVUXDDVDFKRPUWP6
bugzilla.suse.com/1093151
bugzilla.suse.com/1093152
suse.com/security/cve/CVE-2017-17688
suse.com/security/cve/CVE-2017-17689
lists.opensuse.org/archives/list/[email protected]/thread/OTHLYEPMU5SK5PDODY44XQQ6DR7FWSLS
suse.com/security/cve/CVE-2018-12019
suse.com/security/cve/CVE-2018-12020
suse.com/security/cve/CVE-2019-12269