CVE-2017-10784

The Basic authentication code in WEBrick library in Ruby before 2.2.8, 2.3.x before 2.3.5, and 2.4.x through 2.4.1 allows remote attackers to inject terminal emulator escape sequences into its log and possibly execute arbitrary commands via a crafted user name.

Published: 2017-09-19 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2017-10784 is rated High Risk (74/100): CVSS High severity, with high exploitation likelihood (EPSS 16.41%, 97th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +14.29% over the last day, indicating growing attacker interest. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

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

Exploit prediction scoring system (EPSS) score for CVE-2017-10784

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 2.12% 16.41% +14.29%
2 2026-05-22 1.60% 2.12% +0.52%
3 2026-04-18 1.60%

Full EPSS history (53 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-10784

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H 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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]
9.3 2.0 HIGH
AV:N/AC:M/Au:N/C:C/I:C/A:C 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:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
8.6 10.0 [email protected]

Weakness enumeration for CVE-2017-10784

GitHub Security Advisory for CVE-2017-10784

OS Trackers for CVE-2017-10784

vendor priority summary link
alpine CVE-2017-10784: 1 source package rows (ruby); 10 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 0. https://security.alpinelinux.org/vuln/CVE-2017-10784
gentoo normal CVE-2017-10784: 1 GLSA(s) (201710-18), 1 atom(s) (dev-lang/ruby); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2017-10784
redhat medium https://access.redhat.com/security/cve/CVE-2017-10784
suse medium CVE-2017-10784 severity moderate: SUSE including 29 source package names (libruby2_1-2_1-2.1.9-19.3.2, libruby2_5-2_5, …), 219 product×package rows across 73 product lines (HPE Helion OpenStack 8, Image SLES12-SP5-Azure-BYOS, … (73 product lines)): Fixed 140, Known Not Affected 74, Will Not Fix 5. https://www.suse.com/security/cve/CVE-2017-10784/
ubuntu medium CVE-2017-10784 medium priority: Ubuntu including 3 source packages (ruby1.9.1, ruby2.0, ruby2.3), 18 status rows across 6 suites (artful, bionic, trusty, upstream, xenial, zesty): DNE 10, released 4, needs-triage 3, ignored 1. https://ubuntu.com/security/CVE-2017-10784

Affected software / configurations for CVE-2017-10784

Vendor Product Version Raw CPE
ruby-lang ruby <= 2.2.7 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
ruby-lang ruby 2.3.0 cpe:2.3:a:ruby-lang:ruby:2.3.0:*:*:*:*:*:*:*
ruby-lang ruby 2.3.0 cpe:2.3:a:ruby-lang:ruby:2.3.0:preview1:*:*:*:*:*:*
ruby-lang ruby 2.3.0 cpe:2.3:a:ruby-lang:ruby:2.3.0:preview2:*:*:*:*:*:*
ruby-lang ruby 2.3.1 cpe:2.3:a:ruby-lang:ruby:2.3.1:*:*:*:*:*:*:*
ruby-lang ruby 2.3.2 cpe:2.3:a:ruby-lang:ruby:2.3.2:*:*:*:*:*:*:*
ruby-lang ruby 2.3.3 cpe:2.3:a:ruby-lang:ruby:2.3.3:*:*:*:*:*:*:*
ruby-lang ruby 2.3.4 cpe:2.3:a:ruby-lang:ruby:2.3.4:*:*:*:*:*:*:*
ruby-lang ruby 2.4.0 cpe:2.3:a:ruby-lang:ruby:2.4.0:*:*:*:*:*:*:*
ruby-lang ruby 2.4.0 cpe:2.3:a:ruby-lang:ruby:2.4.0:preview1:*:*:*:*:*:*
ruby-lang ruby 2.4.0 cpe:2.3:a:ruby-lang:ruby:2.4.0:preview2:*:*:*:*:*:*
ruby-lang ruby 2.4.0 cpe:2.3:a:ruby-lang:ruby:2.4.0:preview3:*:*:*:*:*:*
ruby-lang ruby 2.4.0 cpe:2.3:a:ruby-lang:ruby:2.4.0:rc1:*:*:*:*:*:*
ruby-lang ruby 2.4.1 cpe:2.3:a:ruby-lang:ruby:2.4.1:*:*:*:*:*:*:*

References for CVE-2017-10784

URL Tags
http://www.securityfocus.com/bid/100853 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1039363 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1042004
https://access.redhat.com/errata/RHSA-2017:3485
https://access.redhat.com/errata/RHSA-2018:0378
https://access.redhat.com/errata/RHSA-2018:0583
https://access.redhat.com/errata/RHSA-2018:0585
https://lists.debian.org/debian-lts-announce/2018/07/msg00012.html
https://security.gentoo.org/glsa/201710-18
https://usn.ubuntu.com/3528-1/
https://usn.ubuntu.com/3685-1/
https://www.debian.org/security/2017/dsa-4031
https://www.ruby-lang.org/en/news/2017/09/14/ruby-2-2-8-released/ Patch Vendor Advisory
https://www.ruby-lang.org/en/news/2017/09/14/ruby-2-3-5-released/ Patch Vendor Advisory
https://www.ruby-lang.org/en/news/2017/09/14/webrick-basic-auth-escape-sequence-injection-cve-2017-10784/ Vendor Advisory
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