Ruby 1.9.3/2.0.0/2.1.0 string.c str_buf_cat Long String data processing

CVSS Meta Temp Score
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CTI Interest Score
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4.8$0-$5k0.00

Summaryinfo

A vulnerability marked as problematic has been reported in Ruby 1.9.3/2.0.0/2.1.0. This vulnerability affects the function str_buf_cat of the file string.c. This manipulation as part of Long String causes data processing. This vulnerability appears as CVE-2014-3916. In addition, an exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Ruby 1.9.3/2.0.0/2.1.0 (Programming Language Software) and classified as problematic. Affected by this vulnerability is the function str_buf_cat of the file string.c. The manipulation as part of a Long String leads to a data processing vulnerability. The CWE definition for the vulnerability is CWE-19. As an impact it is known to affect availability. The summary by CVE is:

The str_buf_cat function in string.c in Ruby 1.9.3, 2.0.0, and 2.1 allows context-dependent attackers to cause a denial of service (segmentation fault and crash) via a long string.

The weakness was presented 04/09/2014 by Hiroshi Shirosaki as Revision 45534 as confirmed commit (Trunk). It is possible to read the advisory at bugs.ruby-lang.org. This vulnerability is known as CVE-2014-3916 since 05/29/2014. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details and also a public exploit are known. Responsible for the vulnerability is the following code: 

capa = (total + 4095) / 4096;

A public exploit has been developed by Ramon de C Valle and been published 2 months after the advisory. It is possible to download the exploit at seclists.org. It is declared as proof-of-concept. The code used by the exploit is:

A = ""
1000000.times do |i|
  A << "a" * 100000
end

Upgrading eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at bugs.ruby-lang.org. The best possible mitigation is suggested to be upgrading to the latest version. A possible mitigation has been published immediately after the disclosure of the vulnerability. The vulnerability will be addressed with the following lines of code:

capa = LONG_MAX - termlen;

The vulnerability is also documented in the databases at X-Force (93505) and SecurityFocus (BID 67705†). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 4.8

VulDB Base Score: 5.3
VulDB Temp Score: 4.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Data processing
CWE: CWE-19
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Author: Ramon de C Valle
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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OpenVAS ID: 801760
OpenVAS Name: Ruby str_buf_cat function Denial-of-Service Vulnerability (Windows)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Patch: bugs.ruby-lang.org

Timelineinfo

04/09/2014 🔍
04/09/2014 +0 days 🔍
05/27/2014 +48 days 🔍
05/27/2014 +0 days 🔍
05/29/2014 +2 days 🔍
06/03/2014 +5 days 🔍
11/16/2014 +166 days 🔍
10/19/2018 +1433 days 🔍

Sourcesinfo

Advisory: Revision 45534
Researcher: Hiroshi Shirosaki
Status: Confirmed

CVE: CVE-2014-3916 (🔍)
GCVE (CVE): GCVE-0-2014-3916
GCVE (VulDB): GCVE-100-13423
X-Force: 93505 - Ruby str_buf_cat() denial of service, Medium Risk
SecurityFocus: 67705 - Ruby 'string.c' Remote Memory Corruption Vulnerability

scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 06/03/2014 16:52
Updated: 10/19/2018 08:11
Changes: 06/03/2014 16:52 (71), 10/19/2018 08:11 (4)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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