Selecting Software Packages for Secure Database Installations

Transcription

1 Selecting Software Packages for Secure Database Installations Afonso Araújo Neto, Marco Vieira This document includes complementary information for the paper Selecting Software Packages for Secure Database Installations which was submitted to the Fifth Latin-American Symposium on Dependable Computing. It contains information regarding the full list of security best practices, the corresponding importance weights and the full gap analysis matrix. Table 1. MS configuration security best practices devised from the analysis of the CIS documents # SECURITY BEST PRACTICE (CIS) Recommendations in CIS documents M O8 O10 S ENVIRONMENT 1 Use a dedicated machine for the database Avoid machines which also run critical network services (naming, authentication, etc) Use Firewalls: on the machine and on the network border Prevent physical access to the MS machine by unauthorized people 1 5 Remove from the network stack all unauthorized protocols Create a specific user to run the MS daemons Restrict MS user access to everything he doesn't need Prevent direct login on the MS user account INSTALLATION SETUP 9 Create a partition for log information Only the MS user should read/write in the log partition 1 11 Create a partition for data Only the MS user should read/write in the data partition 1 13 Separate the MS software from the files Remove/Avoid default elements: 14»»»Remove example databases »»»Change/remove user names/passwords »»»Change remote identification names (SID, etc...) »»»Change TCP/UDP Ports »»»Do not use default SSL certificates 1 19 Separate production and development servers No developer should have access to the production server Use different network segments for production and development servers Verify all the installed MS application files: 22»»»Check and set the owner of the files »»»Set read/running permissions only to authorized users OPERATIONAL PROCEDURES 24 Keep the MS software updated Make regular backups Test the backups 1 1 SYSTEM LEVEL CONFIGURATION 27 Avoid random ports assignment for client connections (firewall configuration) Enforce remote communication encryption with strong algorithms Use server side certificate if possible Use IPs instead of host names to configure access permissions (prevents DNS spoofing) Enforce strong user level authentication Prevent idle connection hijacking Ensure no remote parameters are used in authentication Avoid host based authentication Enforce strong password policies Apply excessive failed logins lock Apply password lifetime control 1 1

2 38 Deny regular password reuse (force periodic change) Use strong encryption in password storage 3 40 Enforce comprehensive logging Verify that the log data cannot be lost (replication is used) Audit sensible information Verify that the audit data cannot be lost (replication is used) 1 1 Ensure no side-channel information leak (don t create/restrict access): 44»»»From configuration files »»»From system variables 1 46»»»From core_dump/trace files »»»From backups of data and configuration files Avoid the interaction between the MS users and the : 48»»»Deny any read/write on file system from MS used »»»Deny any network operation (sending , opening sockets, etc...) »»»Deny access to not needed extended libraries and functionalities »»»Deny access to any information and commands 2 APPLICATION LEVEL CONFIGURATION AND USAGE 52 Remove user rights over system tables Remove user quotas over system areas Implement least privilege policy in rights assignments Avoid ANY and ALL expressions in rights assignments Do not delegate rights assignments No user should have rights to change system properties or configurations Grant privileges to roles/groups instead of users Do not maintain the schema creation SQL files in the server 1 Total number of recomendations Table 2. Complementary DoD configuration best practices # COMPLEMENTARY BEST PRACTICES (DoD) Group 1A Monitor de MS application and configuration files for modifications Operational Procedures 2A Do not use self signed certificates System Level Config. 3A Protect/encrypt application code Appl. Level Config./Usage 4A Audit application code changes Appl. Level Config./Usage 5A Employ stored procedures and views instead of direct table access Appl. Level Config./Usage Best practices weights The following table presents the individual weights given by the experts, the relative importance to the attack surface and the cumulative importance for each best practice. For each contributor, E stands for engineer and A for academic. Best Relative Cumul. E1 E2 A3 A4 E5 A6 E7 A8 A9 Practice Weight Weight ,26% 5,26% ,73% 9,99% ,21% 14,19% ,21% 18,40% ,21% 22,60% ,68% 26,28% ,68% 29,96% ,68% 33,64% ,63% 37,27% ,15% 40,42% ,10% 43,52% ,00% 46,52% ,58% 49,10% ,52% 51,61% ,10% 53,72% ,10% 55,82%

3 ,05% 57,87% ,05% 59,92% ,00% 61,92% ,00% 63,91% ,00% 65,91% ,99% 67,90% ,52% 69,43% ,52% 70,95% ,47% 72,42% ,41% 73,84% ,41% 75,25% ,41% 76,66% ,37% 78,02% ,24% 79,26% ,00% 80,26% ,00% 81,26% ,95% 82,21% ,95% 83,15% ,94% 84,09% ,89% 84,99% ,89% 85,88% ,88% 86,76% ,84% 87,60% ,84% 88,44% ,79% 89,23% ,79% 90,02% ,79% 90,81% ,79% 91,59% ,78% 92,38% ,77% 93,15% ,73% 93,88% ,72% 94,60% 4A ,71% 95,32% ,67% 95,98% ,62% 96,60% ,60% 97,20% ,47% 97,67% ,31% 97,98% 1A ,26% 98,24% ,26% 98,50% ,26% 98,76% ,24% 99,00% 2A ,20% 99,20% ,19% 99,39% 5A ,16% 99,55% ,15% 99,70% ,15% 99,85% 3A ,15% 100,00%

4 Component Target Package 1 Package 2 Package 3 Package 4 Package 5 Package 6 Package 7 Overall results of the experimental evaluation of 7 different software packages. MS Engine Operating system Package N. MP NSMC % SQL Server 2005 Windows P ,5 76% Oracle 10g Red Hat Enterprise Linux ,5 68% Windows P % PostgreSQL 8 Red Hat Enterprise Linux % Windows P ,5 66% MySQL Community Edition 5 Red Hat Enterprise Linux % Windows P ,5 64% GAP ANALISYS MATRI The following table presents the complete gap analysis matrix of the 7 packages, not included in the paper. Security Mechanism (The package offers support for...) Disabling access to extended stored procedures and functions Config. the system to always encrypt a remote connection to the MS Encrypting the connection of developer applications Removing system privileges of MS userids Restricting read/write privileges of a partition to a specific userid Automated installation of MS pending patches Automated installation of pending patches Configuring the MS to store credential information using a reliable encryption scheme Configuring the to store credential information using a reliable encryption scheme Defining all MS passwords during the installation phase Defining all MS userids in the installation phase Defining all passwords during the installation phase Defining all userids during the installation phase Relying the MS on an outside specialized authentication mechanism Relying the on an outside specialized authentication mechanism Removing all privileges of users over all systems tables. Warning MS users, in a password change operation, that their new passwords are weak and cannot be accepted Warning users, in a password change operation, that their new passwords are weak and cannot be accepted A MS authentication procedure that requests only credential information to the remote users An authentication procedure for remote clients that identify individual end users instead of individual applications An authentication procedure that requests only credential information to the remote users Configuring the MS so only administrators have access to log

5 information Configuring the so only admins. have access to log information Configuring the system to drop idle connections after a specific period of inactivity Configuring the system to require that remote clients have the correct server certificate installed Denying login into the MS from a credential with more than a specified number of failed authentication attempts Denying login into the from a credential with more than a specified number of failed authentication attempts Forcing the MS users to change their passwords when they're older than a specified time frame Forcing the users to change their passwords when they're older than a specified time frame Identifying systems privileges of MS userids Setting read/write/execution privileges over files Setting that a userid cannot login Setting who can change configuration files Setting who can change environment variables Specifying privileges in a row/value level Using custom defined SSL certificates for encrypted connections Changing MS userids already in use Changing userids already in use Changing passwords of MS userids already in use Changing passwords of userids already in use Creating an userid with limited privileges Creating file systems partitions Identifying MS userids with default passwords Identifying default MS userids Identifying default userids Identifying userids with default passwords Identifying users with privileges over systems tables Making a backup copy of the database Making a backup copy of the which can be used to restore the environment to its current state Storing the backup in a custom storage place Testing the installation of MS new patches Testing the installation of new patches Using a privilege limited userid to successfully install the MS. Using a privilege limited userid to successfully load a MS process. Warning the admin that the last data backup is not up-to-date anymore Warning the administrator that the last backup is not up-to-date anymore Warning the administrator that there are MS vendor patches remaining to be applied Warning the administrator that there are vendor patches remaining to

6 be applied Allowing the A to not use ANY and ALL expressions Allowing to explicitly state that a particular privilege cannot be delegated Auditing a variety of important MS events Auditing data changes Blocking non-as from delegating their privileges Blocking privileges not inherited from groups/roles Blocking the usage of ANY and ALL expressions in privileges granting Changing listening TCP/UDP ports Changing remote identification information already in use. (e.g., SID) Config. the MS so only As have access to audited information Configuring the system to always establish connections through the same TCP/UDP ports during the installation phase. Configuring the system to always establish connections through the same TCP/UDP ports. Defining all remote identification information during the installation phase Defining listening TCP/UDP ports during the installation phase Disabling the generation of core_dump files Disabling the generation of trace files Encrypting backups with a reliable encryption algorithm Identifying available functions that interact with the operating system Preventing specifying sensitive information in configuration files. (e.g., not require specifying password in configuration files, etc.) Preventing the general use of sensitive information in systems variables Preventing the installation of a database example during installation Removing quotas over systems areas Setting and discarding a complex password for a userid Setting privileges to groups or roles Setting the owner of files Specifying important events which occur in the MS that should generate a finger print Specifying important events which occur in the that should generate a finger print Specifying privileges in a column level Specifying privileges in a database level Specifying privileges in a table level Warning MS users that their passwords are older than a specified time frame Warning users that their passwords are older than a specified time frame Warning the administrator if any important configuration or file was modified Writing procedures that generate a trace for data changes Creating stored procedures Creating views Disabling a network protocol

7 Identifying active protocols in the network stack Identifying available extended functions in general Identifying available functions that can be used to perform network operations Identifying available functions that can be used to read/write in the file system Identifying example databases Identifying users with quotas over systems areas Removing a database Selecting a different partition for log information Selecting a different partition than the main partition for auditing info Selecting a different partition than the main partition for MS log information Selecting a different partition than the main partition for the data files Setting/unsetting access privileges over peripherals Setting/unsetting read/write/execute privileges over files Testing if a recently created backup correctly restores the database data to its corresponding state Testing if a recently created backup correctly restores the system to its corresponding state Warning administrators of ANY and ALL expressions used in privileges assignments Warning admin of users with the power of delegating their privileges