SOLARIS 9 SPARC SECURITY TECHNICAL IMPLEMENTATION GUIDE

Internet Network News (INN) servers access Usenet newsfeeds and store newsgroup articles. INN servers use the Network News Transfer Protocol (NNTP) to transfer information from the Usenet to the server and from the server to authorized remote hosts. If this function is necessary to support a valid mission requirement, its use must be authorized and approved in the system accreditation package.

The executable search path (typically the PATH environment variable) contains a list of directories for the shell to search to find executables. If this path includes the current working directory or other relative paths, executables in these directories may be executed instead of system commands. This variable is formatted as a colon-separated list of directories. If there is an empty entry, such as a leading or trailing colon, or two consecutive colons, this is interpreted as the current working directory. Paths starting with a slash (/) are absolute paths.

The rmmount.conf file controls the mounting of removable media on a Solaris system. Removable media is not to be trusted with privileged access, and therefore the filesystems must be mounted with the nosuid option, which prevents any executables with the setuid bit set on this filesystem from running with owner privileges.

A synchronized system clock is critical for the enforcement of time-based policies and the correlation of logs and audit records with other systems. If an illicit time source is used for synchronization, the integrity of system logs and the security of the system could be compromised. If the configuration files controlling time synchronization are not owned by a system account, unauthorized modifications could result in the failure of time synchronization.

A synchronized system clock is critical for the enforcement of time-based policies and the correlation of logs and audit records with other systems. If an illicit time source is used for synchronization, the integrity of system logs and the security of the system could be compromised. If the configuration files controlling time synchronization are not protected, unauthorized modifications could result in the failure of time synchronization.

The library preload list environment variable contains a list of libraries for the dynamic linker to load before loading the libraries required by the binary. If this list contains paths to libraries relative to the current working directory, unintended libraries may be preloaded. This variable is formatted as a space-separated list of libraries. Paths starting with (/) are absolute paths.

The resolv.conf (or equivalent) file configures the system's DNS resolver. DNS is used to resolve host names to IP addresses. If DNS configuration is modified maliciously, host name resolution may fail or return incorrect information. DNS may be used by a variety of system security functions, such as time synchronization, centralized authentication, and remote system logging.

The /etc/hosts file (or equivalent) configures local host name to IP address mappings that typically take precedence over DNS resolution. If this file is maliciously modified, it could cause the failure or compromise of security functions requiring name resolution, which may include time synchronization, centralized authentication, and remote system logging.

The nsswitch.conf file (or equivalent) configures the source of a variety of system security information including account, group, and host lookups. Malicious changes could prevent the system from functioning or compromise system security.

The /etc/group file is critical to system security and must be owned by a privileged user. The group file contains a list of system groups and associated information.

Group passwords are typically shared and should not be used. Additionally, if password hashes are readable by non-administrators, the passwords are subject to attack through lookup tables or cryptographic weaknesses in the hashes.

To prevent unauthorized access or manipulation of system audit logs, the tools for manipulating those logs must be protected.

To prevent unauthorized access or manipulation of system audit logs, the tools for manipulating those logs must be protected.

If the group of the cron.allow is not set to root, bin, or sys, the possibility exists for an unauthorized user to view or edit the list of users permitted to use cron. Unauthorized modification of this file could cause Denial of Service to authorized cron users or provide unauthorized users with the ability to run cron jobs.

Cron daemon control files restrict the scheduling of automated tasks and must be protected. Unauthorized modification of the cron.deny file could result in Denial of Service to authorized cron users or could provide unauthorized users with the ability to run cron jobs.

If the group owner of the at.deny file is not set to root, bin, or sys, unauthorized users could be allowed to view or edit sensitive information contained within the file. Unauthorized modification could result in Denial of Service to authorized "at" users or provide unauthorized users with the ability to run "at" jobs.

The rlogind process provides a typically unencrypted, host-authenticated remote access service. SSH should be used in place of this service.

Unauthorized users must not be allowed to access or modify the /etc/syslog.conf file.

The Cipher-Block Chaining (CBC) mode of encryption as implemented in the SSHv2 protocol is vulnerable to chosen plain text attacks and must not be used.

If a public host key file is modified by an unauthorized user, the SSH service may be compromised.

GSSAPI authentication is used to provide additional authentication mechanisms to applications. Allowing GSSAPI authentication through SSH exposes the system’s GSSAPI to remote hosts, increasing the attack surface of the system. GSSAPI authentication must be disabled unless needed.

If compression is allowed in an SSH connection prior to authentication, vulnerabilities in the compression software could result in compromise of the system from an unauthenticated connection, potentially with root privileges.

DHCP allows for the unauthenticated configuration of network parameters on the system by exchanging information with a DHCP server.

To prevent the installation of software from unauthorized sources, the system package management tool must use cryptographic algorithms to verify the packages are authentic.

If a user is assigned the GID of a group not existing on the system, and a group with the same GID is subsequently created, the user may have unintended rights to the group.

The use of longer passwords reduces the ability of attackers to successfully obtain valid passwords using guessing or exhaustive search techniques by increasing the password search space.

NIS/NIS+/yp files are part of the system's identification and authentication processes and are, therefore, critical to system security. Failure to give ownership of sensitive files or utilities to root or bin provides the designated owner and unauthorized users with the potential to access sensitive information or change the system configuration which could weaken the system's security posture.

NIS/NIS+/yp files are part of the system's identification and authentication processes and are, therefore, critical to system security. Unauthorized modification of these files could compromise these processes and the system.

If a user has a home directory defined that does not exist, the user may be given the / directory, by default, as the current working directory upon logon. This could create a Denial of Service because the user would not be able to perform useful tasks in this location.

If system start-up files do not have a group owner of root or a system group, the files may be modified by malicious users or intruders.

Without privileged group owners, audio devices will be vulnerable to being used as eaves-dropping devices by malicious users or intruders to possibly listen to conversations containing sensitive information.

Failure to give ownership of system audit log files to root provides the designated owner and unauthorized users with the potential to access sensitive information.

If a user can write to the audit logs, audit trails can be modified or destroyed and system intrusion may not be detected. System audit logs are those files generated from the audit system and do not include activity, error, or other log files created by application software.

If the system is not configured to audit certain activities and write them to an audit log, it is more difficult to detect and track system compromises and damages incurred during a system compromise.

If the system is not configured to audit certain activities and write them to an audit log, it is more difficult to detect and track system compromises and damages incurred during a system compromise.

A cron.allow file that is readable and/or writable by other than root could allow potential intruders and malicious users to use the file contents to help discern information, such as who is allowed to execute cron programs, which could be harmful to overall system and network security.

To protect the integrity of scheduled system jobs and to prevent malicious modification to these jobs, crontab files must be secured.

To protect the integrity of scheduled system jobs and to prevent malicious modification to these jobs, crontab files must be secured. Failure to give group-ownership of cron or crontab directories to a system group provides the designated group and unauthorized users with the potential to access sensitive information or change the system configuration which could weaken the system's security posture.

If file permissions for cron.deny are more permissive than 0600, sensitive information could be viewed or edited by unauthorized users.

Cron daemon control files restrict the scheduling of automated tasks and must be protected.

On some systems, if there is no at.allow file and there is an empty at.deny file, then the system assumes everyone has permission to use the at facility. This could create an insecure setting in the case of malicious users or system intruders.

If the owner of the at.allow file is not set to root, bin, or sys, unauthorized users could be allowed to view or edit sensitive information contained within the file.

Kernel core dumps may contain the full contents of system memory at the time of the crash. As the system memory may contain sensitive information, it must be protected accordingly. If the kernel core dump data directory is not owned by root, the core dumps contained in the directory may be subject to unauthorized access.

One use of initial TCP sequence numbers is to verify bidirectional communication between two hosts, which provides some protection against spoofed source addresses being used by the connection originator. If the initial TCP sequence numbers for a host can be determined by an attacker, it may be possible to establish a TCP connection from a spoofed source address without bidirectional communication.

If the group owner of the traceroute command has not been set to a system group, unauthorized users could have access to the command and use it to gain information regarding a network's topology inside of the firewall. This information may allow an attacker to determine trusted routers and other network information possibly leading to system and network compromise.

If the file ftpusers is not owned by root, an unauthorized user may modify the file to allow unauthorized accounts to use FTP.

Failure to give ownership of the NFS export configuration file to root provides the designated owner and possible unauthorized users with the potential to change system configuration which could weaken the system's security posture.

Failure to display the login banner prior to a logon attempt will negate legal proceedings resulting from unauthorized access to system resources.

The use of separate filesystems for different paths can protect the system from failures resulting from a filesystem becoming full or failing.

SSHv1 is not a DoD-approved protocol and has many well-known vulnerability exploits. Exploits of the SSH daemon could provide immediate root access to the system.

Unauthorized access could destroy the integrity of the library files.

If the mesg -n or mesg n command is not placed into the system profile, messaging can be used to cause a Denial of Service attack.

The Internet service daemon configuration files must be protected as malicious modification could cause Denial of Service or increase the attack surface of the system.

If the group owner of /etc/syslog.conf is not root, bin, or sys, unauthorized users could be permitted to view, edit, or delete important system messages handled by the syslog facility.

The /etc/hosts file (or equivalent) configures local host name to IP address mappings that typically take precedence over DNS resolution. If this file is maliciously modified, it could cause the failure or compromise of security functions requiring name resolution, which may include time synchronization, centralized authentication, and remote system logging.

The /etc/passwd file contains the list of local system accounts. It is vital to system security and must be protected from unauthorized modification.

The /etc/shadow file contains the list of local system accounts. It is vital to system security and must be protected from unauthorized modification. The file also contains password hashes which must not be accessible to users other than root.

Failure to give ownership of system configuration files to root or a system group provides the designated owner and unauthorized users with the potential to change the system configuration which could weaken the system's security posture.

LDAP can be used to provide user authentication and account information, which are vital to system security. The LDAP client configuration must be protected from unauthorized modification.

LDAP can be used to provide user authentication and account information, which are vital to system security. The LDAP client configuration must be protected from unauthorized modification.

If the system's access control program is not configured with appropriate rules for allowing and denying access to system network resources, services may be accessible to unauthorized hosts.

Audit_user is a sensitive file that, if compromised, would allow a malicious user to select auditing parameters to ignore his sessions. This would allow malicious operations the auditing subsystem would not log for that user.

Excessive permissions on the hosts.nntp.nolimit file may allow unauthorized modification which could lead to Denial-of-Service to authorized users or provide access to unauthorized users.

File permissions more permissive than 0600 for /etc/news/passwd.nntp may allow access to privileged information by system intruders or malicious users.

The Solaris audit_user file allows for selective auditing or non-auditing of features for certain users. If it is not protected, it could be compromised and used to mask audit events. This could cause the loss of valuable forensics data in the case of a system compromise.

If an anonymous FTP account has been configured to use a functional shell, attackers could gain access to the shell if the account is compromised.

Changing the root home directory to something other than / and assigning it a 0700 protection makes it more difficult for intruders to manipulate the system by reading the files that root places in its default directory. It also gives root the same discretionary access control for root's home directory as for the other plain user home directories.

The executable search path (typically the PATH environment variable) contains a list of directories for the shell to search to find executables. If this path includes the current working directory or other relative paths, executables in these directories may be executed instead of system commands. This variable is formatted as a colon-separated list of directories. If there is an empty entry, such as a leading or trailing colon or two consecutive colons, this is interpreted as the current working directory. Entries starting with a slash (/) are absolute paths.

Restricting permissions will protect the files from unauthorized modification.

The /etc/shadow file contains the list of local system accounts. It is vital to system security and must be protected from unauthorized modification. The file also contains password hashes which must not be accessible to users other than root.

The services file is critical to the proper operation of network services and must be protected from unauthorized modification. Unauthorized modification could result in the failure of network services.

If the userlist file does not exist, then an unauthorized user may exist in the /etc/passwd file.

A permission mask not set to the required level could allow unauthorized access to sensitive system files and resources.