CVE-2019-16255
Publication date 20 November 2019
Last updated 11 July 2025
Ubuntu priority
Cvss 3 Severity Score
Description
Ruby through 2.4.7, 2.5.x through 2.5.6, and 2.6.x through 2.6.4 allows code injection if the first argument (aka the "command" argument) to Shell#[] or Shell#test in lib/shell.rb is untrusted data. An attacker can exploit this to call an arbitrary Ruby method.
From the Ubuntu Security Team
It was discovered that JRuby did not properly sanitize input to Shell#[] and its alias Shell#test. An attacker could use this vulnerability to execute arbitrary commands.
Status
| Package | Ubuntu Release | Status | 
|---|---|---|
| jruby | 25.10 questing | 
                              
                               
                                Needs evaluation 
                                
                               
                             |      
                          
                            
                          
                        
                      
| 25.04 plucky | 
                              
                               
                                Needs evaluation 
                                
                               
                             |      
                          
                            
                          
                        
                      |
| 24.04 LTS noble | 
                              
                               
                                Needs evaluation 
                                
                               
                             |      
                          
                            
                          
                        
                      |
| 20.04 LTS focal | 
                              
                               
                                Needs evaluation 
                                
                               
                             |      
                          
                            
                          
                        
                      |
| 18.04 LTS bionic | 
                              
                               
                                Needs evaluation 
                                
                               
                             |      
                          
                            
                          
                        
                      |
| 16.04 LTS xenial | 
                              
                               
                                Needs evaluation 
                                
                               
                             |      
                          
                            
                          
                        
                      |
| 14.04 LTS trusty | 
                              
                               
                                Fixed 1.5.6-9+deb8u2build0.14.04.1~esm2 
                                
                                   
                             |      
                          
                            
                          
                        
                      |
| ruby2.3 | 25.10 questing | Not in release | 
| 25.04 plucky | Not in release | |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release | |
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | 
                              
                               
                                Fixed 2.3.1-2~ubuntu16.04.14 
                                
                               
                             |      
                          
                            
                          
                        
                      |
| 14.04 LTS trusty | Not in release | |
| ruby2.5 | 25.10 questing | Not in release | 
| 25.04 plucky | Not in release | |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release | |
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | 
                              
                               
                                Fixed 2.5.1-1ubuntu1.6 
                                
                               
                             |      
                          
                            
                          
                        
                      |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | 
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Get Ubuntu Pro 30-day free trialSeverity score breakdown
| Parameter | Value | 
|---|---|
| Base score | 
                      
                      
                         | 
                  
| Attack vector | Network | 
| Attack complexity | High | 
| Privileges required | None | 
| User interaction | None | 
| Scope | Unchanged | 
| Confidentiality | High | 
| Integrity impact | High | 
| Availability impact | High | 
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H | 
References
Related Ubuntu Security Notices (USN)
- USN-4201-1
 - Ruby vulnerabilities
 - 26 November 2019