DLA-1421-1

An exploitable heap overflow vulnerability exists in the Fiddle::Function.new "initialize" function functionality of Ruby. In Fiddle::Function.new "initialize" heap buffer "arg_types" allocation is made based on args array length. Specially constructed object passed as element of args array can increase this array size after mentioned allocation and cause heap overflow.

The openssl gem for Ruby uses the same initialization vector (IV) in GCM Mode (aes-*-gcm) when the IV is set before the key, which makes it easier for context-dependent attackers to bypass the encryption protection mechanism.

Ruby before 2.4.2, 2.3.5, and 2.2.8 is vulnerable to a malicious format string which contains a precious specifier (*) with a huge minus value. Such situation can lead to a buffer overrun, resulting in a heap memory corruption or an information disclosure from the heap.

RubyGems version 2.6.12 and earlier is vulnerable to maliciously crafted gem specifications that include terminal escape characters. Printing the gem specification would execute terminal escape sequences.

RubyGems version 2.6.12 and earlier is vulnerable to maliciously crafted gem specifications to cause a denial of service attack against RubyGems clients who have issued a `query` command.

RubyGems version 2.6.12 and earlier fails to validate specification names, allowing a maliciously crafted gem to potentially overwrite any file on the filesystem.

RubyGems version 2.6.12 and earlier is vulnerable to a DNS hijacking vulnerability that allows a MITM attacker to force the RubyGems client to download and install gems from a server that the attacker controls.

RubyGems versions between 2.0.0 and 2.6.13 are vulnerable to a possible remote code execution vulnerability. YAML deserialization of gem specifications can bypass class white lists. Specially crafted serialized objects can possibly be used to escalate to remote code execution.

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 decode method in the OpenSSL::ASN1 module in Ruby before 2.2.8, 2.3.x before 2.3.5, and 2.4.x through 2.4.1 allows attackers to cause a denial of service (interpreter crash) via a crafted string.

Ruby through 2.2.7, 2.3.x through 2.3.4, and 2.4.x through 2.4.1 can expose arbitrary memory during a JSON.generate call. The issues lies in using strdup in ext/json/ext/generator/generator.c, which will stop after encountering a '\0' byte, returning a pointer to a string of length zero, which is not the length stored in space_len.

Ruby before 2.4.3 allows Net::FTP command injection. Net::FTP#get, getbinaryfile, gettextfile, put, putbinaryfile, and puttextfile use Kernel#open to open a local file. If the localfile argument starts with the "|" pipe character, the command following the pipe character is executed. The default value of localfile is File.basename(remotefile), so malicious FTP servers could cause arbitrary command execution.

Ruby before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1 allows an HTTP Response Splitting attack. An attacker can inject a crafted key and value into an HTTP response for the HTTP server of WEBrick.

The lazy_initialize function in lib/resolv.rb in Ruby through 2.4.3 uses Kernel#open, which might allow Command Injection attacks, as demonstrated by a Resolv::Hosts::new argument beginning with a '|' character, a different vulnerability than CVE-2017-17405. NOTE: situations with untrusted input may be highly unlikely.

RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series: 2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5 series: 2.5.0 and earlier, prior to trunk revision 62422 contains a infinite loop caused by negative size vulnerability in ruby gem package tar header that can result in a negative size could cause an infinite loop.. This vulnerability appears to have been fixed in 2.7.6.

RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series: 2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5 series: 2.5.0 and earlier, prior to trunk revision 62422 contains a Improper Verification of Cryptographic Signature vulnerability in package.rb that can result in a mis-signed gem could be installed, as the tarball would contain multiple gem signatures.. This vulnerability appears to have been fixed in 2.7.6.

RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series: 2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5 series: 2.5.0 and earlier, prior to trunk revision 62422 contains a Improper Input Validation vulnerability in ruby gems specification homepage attribute that can result in a malicious gem could set an invalid homepage URL. This vulnerability appears to have been fixed in 2.7.6.

RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series: 2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5 series: 2.5.0 and earlier, prior to trunk revision 62422 contains a Cross Site Scripting (XSS) vulnerability in gem server display of homepage attribute that can result in XSS. This attack appear to be exploitable via the victim must browse to a malicious gem on a vulnerable gem server. This vulnerability appears to have been fixed in 2.7.6.

RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series: 2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5 series: 2.5.0 and earlier, prior to trunk revision 62422 contains a Directory Traversal vulnerability in gem installation that can result in the gem could write to arbitrary filesystem locations during installation. This attack appear to be exploitable via the victim must install a malicious gem. This vulnerability appears to have been fixed in 2.7.6.

Directory traversal vulnerability in the Dir.mktmpdir method in the tmpdir library in Ruby before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1 might allow attackers to create arbitrary directories or files via a .. (dot dot) in the prefix argument.

In Ruby before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1, an attacker can pass a large HTTP request with a crafted header to WEBrick server or a crafted body to WEBrick server/handler and cause a denial of service (memory consumption).

In Ruby before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1, an attacker controlling the unpacking format (similar to format string vulnerabilities) can trigger a buffer under-read in the String#unpack method, resulting in a massive and controlled information disclosure.

In Ruby before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1, the UNIXServer.open and UNIXSocket.open methods are not checked for null characters. It may be connected to an unintended socket.

In Ruby before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1, the Dir.open, Dir.new, Dir.entries and Dir.empty? methods do not check NULL characters. When using the corresponding method, unintentional directory traversal may be performed.