Package Instance

Predictable tmp File Path Vulnerability
A known /tmp filename is used during passenger-install-nginx-module execution, which can allow local attackers to gain the privileges of the passenger user.

Incorrect Permission Assignment for Critical Resource
An Incorrect Access Control vulnerability in SpawningKit in Phusion Passenger allows a Passenger-managed malicious application, upon spawning a child process, to report an arbitrary different PID back to Passenger's process manager. If the malicious application then generates an error, it would cause Passenger's process manager to kill said reported arbitrary PID.

Information Exposure
Given a Passenger-spawned application process that reports that it listens on a certain Unix domain socket, if any of the parent directories of said socket are writable by a normal user that is not the application's user, then that non-application user can swap that directory with something else, resulting in traffic being redirected to a non-application user's process through an alternative Unix domain socket.

Header overwriting
It is possible in some cases, for clients to overwrite headers set by the server, resulting in a medium level security issue. Passenger 5 uses an SCGI-inspired format to pass headers to Ruby/Python applications, while Passenger 4 uses an SCGI-inspired format to pass headers to all applications. This implies a conversion to UPPER_CASE_WITH_UNDERSCORES whereby the difference between characters like '-' and '_' is lost. See "Affected use-cases" in provided link to establish wether one particular application is affected.

Instance Directory Creation Symlink Arbitrary File Overwrite
Passenger Gem for Ruby contains a flaw as the program creates the server instance directory insecurely. It is possible for a local attacker to use a symlink attack against the directory to cause the program to unexpectedly overwrite an arbitrary file.

Phusion Passenger denial of service
The http parser in Phusion Passenger 6.0.21 through 6.0.25
before 6.0.26 allows a denial of service during parsing of
a request with an invalid HTTP method.

Utils.cpp Temporary Directory Creation Symlink Local Privilege Escalation
This package contains a flaw as the program creates temporary directories insecurely. It is possible for a local attacker to use a symlink attack against the Utils.cpp file to allow the attacker to gain elevated privileges.

Incorrect Permission Assignment for Critical Resource
An issue was discovered in Phusion Passenger. The set of groups (gidset) is not set correctly, leaving it up to randomness (i.e., uninitialized memory) which supplementary groups are actually being set while lowering privileges.

Information Exposure
If Passenger is running as root, it is possible to list the contents of arbitrary files on a system by symlinking a file named REVISION from the application root folder to a file of choice and querying `passenger-status --show=xml`.

Improper Link Resolution Before File Access
During the spawning of a malicious Passenger-managed application, SpawningKit in Phusion Passenger allows such applications to replace key files or directories in the spawning communication directory with symlinks. This then could result in arbitrary reads and writes, which in turn can result in information disclosure and privilege escalation.

Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition)
A race condition in the nginx module in Phusion Passenger allows local escalation of privileges when a non-standard `passenger_instance_registry_dir` with insufficiently strict permissions is configured. Replacing a file with a symlink after the file was created, but before it was chowned, leads to the target of the link being chowned via the path. Targeting sensitive files such as root's crontab file allows privilege escalation.