CVE-2017-17688

Exp

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

Published: 2018-05-16 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-17688 is rated High Exploit Risk (73.5/100): CVSS Medium severity, with high exploitation likelihood (EPSS 5.57%, 92th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +2.73% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2017-17688

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2017-17688

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 2.84% 5.57% +2.73%
2 2026-05-16 3.27% 2.84% -0.42%
3 2026-04-01 — 3.27% —

Full EPSS history (21 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-17688

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.0 MEDIUM
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2017-17688

OS Trackers for CVE-2017-17688

vendor priority summary link
debian not yet assigned CVE-2017-17688 not yet assigned priority: Debian including 1 source packages (enigmail), 1 status rows across 1 suites (bullseye): resolved 1. https://security-tracker.debian.org/tracker/CVE-2017-17688
redhat medium — https://access.redhat.com/security/cve/CVE-2017-17688
suse medium CVE-2017-17688 severity moderate: SUSE including 20 source package names (enigmail, enigmail-2.0.5-1.2, …), 98 product×package rows across 43 product lines (SUSE Enterprise Storage 7, SUSE Linux Enterprise Desktop 12 SP3, … (43 product lines)): Known Not Affected 90, Fixed 8. https://www.suse.com/security/cve/CVE-2017-17688/
ubuntu medium CVE-2017-17688 medium priority: Ubuntu including 1 source packages (enigmail), 7 status rows across 7 suites (artful, bionic, cosmic, disco, trusty, upstream, xenial): not-affected 4, DNE 1, ignored 1, released 1. https://ubuntu.com/security/CVE-2017-17688

Affected software / configurations for CVE-2017-17688

Vendor Product Version Raw CPE
apple mail — cpe:2.3:a:apple:mail:-:*:*:*:*:*:*:*
apple mail — cpe:2.3:a:apple:mail:-:*:*:*:*:iphone_os:*:*
bloop airmail — cpe:2.3:a:bloop:airmail:-:*:*:*:*:*:*:*
emclient emclient — cpe:2.3:a:emclient:emclient:-:*:*:*:*:*:*:*
flipdogsolutions maildroid — cpe:2.3:a:flipdogsolutions:maildroid:-:*:*:*:*:*:*:*
freron mailmate — cpe:2.3:a:freron:mailmate:-:*:*:*:*:*:*:*
horde horde_imp — cpe:2.3:a:horde:horde_imp:-:*:*:*:*:*:*:*
microsoft outlook 2007 cpe:2.3:a:microsoft:outlook:2007:*:*:*:*:*:*:*
mozilla thunderbird — cpe:2.3:a:mozilla:thunderbird:-:*:*:*:*:*:*:*
postbox-inc postbox — cpe:2.3:a:postbox-inc:postbox:-:*:*:*:*:*:*:*
r2mail2 r2mail2 — cpe:2.3:a:r2mail2:r2mail2:-:*:*:*:*:*:*:*
roundcube webmail — cpe:2.3:a:roundcube:webmail:-:*:*:*:*:*:*:*

References for CVE-2017-17688

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