Ruby up to 2.2.8/2.3.4/2.4.0 WEBrick Library Escape Sequence improper authentication

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.4	$0-$5k	0.00

Summaryinfo

A vulnerability identified as critical has been detected in Ruby up to 2.2.8/2.3.4/2.4.0. Affected by this vulnerability is an unknown functionality of the component WEBrick Library. This manipulation as part of Escape Sequence causes improper authentication. This vulnerability appears as CVE-2017-10784. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Ruby up to 2.2.8/2.3.4/2.4.0 (Programming Language Software) and classified as critical. Affected by this vulnerability is some unknown functionality of the component WEBrick Library. The manipulation as part of a Escape Sequence leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The bug was discovered 09/15/2015. The weakness was presented 09/19/2017 (Website). It is possible to read the advisory at securitytracker.com. This vulnerability is known as CVE-2017-10784 since 07/01/2017. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available.

The vulnerability was handled as a non-public zero-day exploit for at least 735 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 103471 (Debian DLA-1113-1 : ruby1.8 security update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Debian Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 176210 (Debian Security Update for ruby2.3 (DSA 4031-1)).

Upgrading to version 2.2.9, 2.3.5 or 2.4.1 eliminates this vulnerability. A possible mitigation has been published 1 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (103471), SecurityFocus (BID 100853†) and CERT Bund (WID-SEC-2026-1423). See VDB-106032, VDB-106723, VDB-106848 and VDB-107761 for similar entries. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Open Source CentOS
• Debian Linux
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• Open Source Ruby

Productinfo

Type

• Programming Language Software

Name

• Ruby

Version

• 2.0
• 2.1
• 2.2
• 2.2.0
• 2.2.1
• 2.2.2
• 2.2.3
• 2.2.4
• 2.2.5
• 2.2.6
• 2.2.7
• 2.2.8
• 2.3
• 2.3.0
• 2.3.1
• 2.3.2
• 2.3.3
• 2.3.4
• 2.4.0

License

• open-source

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.6
VulDB Meta Temp Score: 7.4

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.8
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Improper authentication
CWE: CWE-287
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 103471
Nessus Name: Debian DLA-1113-1 : ruby1.8 security update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 830183
OpenVAS Name: Debian Security Advisory DSA 4031-1 (ruby2.3 - security update)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: Ruby 2.2.9/2.3.5/2.4.1

Timelineinfo

09/15/2015 🔍
07/01/2017 +655 days 🔍
09/14/2017 +75 days 🔍
09/19/2017 +5 days 🔍
09/19/2017 +0 days 🔍
09/20/2017 +1 days 🔍
09/26/2017 +6 days 🔍
09/27/2017 +1 days 🔍
05/10/2026 +3147 days 🔍

Sourcesinfo

Advisory: RHSA-2017:3485⛔
Researcher: Yusuke Endoh.
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2017-10784 (🔍)
GCVE (CVE): GCVE-0-2017-10784
GCVE (VulDB): GCVE-100-106843

OVAL: 🔍

SecurityFocus: 100853 - Ruby CVE-2017-10784 Security Bypass Vulnerability
SecurityTracker: 1039363
CERT Bund: WID-SEC-2026-1423 - Ruby: Mehrere Schwachstellen

See also: 🔍

Entryinfo

Created: 09/20/2017 09:00
Updated: 05/10/2026 07:53
Changes: 09/20/2017 09:00 (79), 11/17/2019 18:03 (4), 01/13/2021 13:00 (3), 01/13/2021 13:07 (1), 12/29/2022 13:13 (3), 05/10/2026 07:53 (24)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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