HOMEVULNERABILITIESCVE-2017-17688
MEDIUM

CVE-2017-17688

NVD-CWE-noinfoPublished: May 16, 2018· Updated: Jun 17, 2026

5.9
CVSS v3.1

Official 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

NVD Source

Technical Analysis

CVE-2017-17688 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 5.9.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityHigh
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityNone
AvailabilityNone
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected Vendors & Products

Apple1 product(s)
mail
bloop1 product(s)
airmail
emclient1 product(s)
emclient
flipdogsolutions1 product(s)
maildroid
freron1 product(s)
mailmate
horde1 product(s)
horde imp
Microsoft1 product(s)
outlook
Mozilla1 product(s)
thunderbird
postbox-inc1 product(s)
postbox
r2mail21 product(s)
r2mail2
roundcube1 product(s)
webmail
Source: NVD CPE · 11 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

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

All References (20)

→
http://flaked.sockpuppet.org/2018/05/16/a-unified-timeline.htmlThird Party Advisory
→
http://www.securityfocus.com/bid/104162Third Party Advisory · VDB Entry
→
http://www.securitytracker.com/id/1040904Third Party Advisory · VDB Entry
→
https://efail.deExploit · Mitigation · Third Party Advisory
→
https://lists.gnupg.org/pipermail/gnupg-users/2018-May/060334.htmlThird Party Advisory
→
https://news.ycombinator.com/item?id=17066419Issue Tracking · Third Party Advisory
→
https://protonmail.com/blog/pgp-vulnerability-efailIssue Tracking · Third Party Advisory
→
https://twitter.com/matthew_d_green/status/995996706457243648Third Party Advisory
→
https://www.patreon.com/posts/cybersecurity-15-18814817Issue Tracking · Third Party Advisory
→
https://www.synology.com/support/security/Synology_SA_18_22Third Party Advisory
→
http://flaked.sockpuppet.org/2018/05/16/a-unified-timeline.htmlThird Party Advisory
→
http://www.securityfocus.com/bid/104162Third Party Advisory · VDB Entry
→
http://www.securitytracker.com/id/1040904Third Party Advisory · VDB Entry
→
https://efail.deExploit · Mitigation · Third Party Advisory
→
https://lists.gnupg.org/pipermail/gnupg-users/2018-May/060334.htmlThird Party Advisory

Quick Facts

CVE IDCVE-2017-17688
CVSS Score5.9 / 10
SeverityMEDIUM
WeaknessNVD-CWE-noinfo
CISA KEVNo
Affected11 vendor(s)
PublishedMay 16, 2018

Related CVEs (NVD-CWE-noinfo)

CVE-2022-21390
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CVE-2022-21275
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CVE-2022-21389
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CVE-2021-41873
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CVE-2022-37968
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Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2017-17688 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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