CVE-2017-2343

The Integrated User Firewall (UserFW) feature was introduced in Junos OS version 12.1X47-D10 on the Juniper SRX Series devices to provide simple integration of user profiles on top of the existing firewall polices. As part of an internal security review of the UserFW services authentication API, hardcoded credentials were identified and removed which can impact both the SRX Series device, and potentially LDAP and Active Directory integrated points. An attacker may be able to completely compromise SRX Series devices, as well as Active Directory servers and services. When Active Directory is compromised, it may allow access to user credentials, workstations, servers performing other functions such as email, database, etc. Inter-Forest Active Directory deployments may also be at risk as the attacker may gain full administrative control over one or more Active Directories depending on the credentials supplied by the administrator of the AD domains and SRX devices performing integrated authentication of users, groups and devices. To identify if your device is potentially vulnerable to exploitation, check to see if the service is operating; from CLI review the following output: root@SRX-Firewall# run show services user-identification active-directory-access domain-controller status extensive A result of Status: Connected will indicate that the service is active on the device. To evaluate if user authentication is occurring through the device: root@SRX-Firewall# run show services user-identification active-directory-access active-directory-authentication-table all Next review the results to see if valid users and groups are returned. e.g. Domain: juniperlab.com Total entries: 3 Source IP Username groups state 172.16.26.1 administrator Valid 192.168.26.2 engg01 engineers Valid 192.168.26.3 guest01 guests Valid Domain: NULL Total entries: 8 Source IP Username groups state 192.168.26.4 Invalid 192.168.26.5 Invalid This will also indicate that Valid users and groups are authenticating through the device. Affected releases are Juniper Networks Junos OS 12.3X48 from 12.3X48-D30 and prior to 12.3X48-D35 on SRX series; 15.1X49 from 15.1X49-D40 and prior to 15.1X49-D50 on SRX series. Devices on any version of Junos OS 12.1X46, or 12.1X47 are unaffected by this issue.

Weakness

The product contains hard-coded credentials, such as a password or cryptographic key, which it uses for its own inbound authentication, outbound communication to external components, or encryption of internal data.

Affected Software

Extended Description

Hard-coded credentials typically create a significant hole that allows an attacker to bypass the authentication that has been configured by the product administrator. This hole might be difficult for the system administrator to detect. Even if detected, it can be difficult to fix, so the administrator may be forced into disabling the product entirely. There are two main variations:

In the Inbound variant, a default administration account is created, and a simple password is hard-coded into the product and associated with that account. This hard-coded password is the same for each installation of the product, and it usually cannot be changed or disabled by system administrators without manually modifying the program, or otherwise patching the product. If the password is ever discovered or published (a common occurrence on the Internet), then anybody with knowledge of this password can access the product. Finally, since all installations of the product will have the same password, even across different organizations, this enables massive attacks such as worms to take place. The Outbound variant applies to front-end systems that authenticate with a back-end service. The back-end service may require a fixed password which can be easily discovered. The programmer may simply hard-code those back-end credentials into the front-end product. Any user of that program may be able to extract the password. Client-side systems with hard-coded passwords pose even more of a threat, since the extraction of a password from a binary is usually very simple.

Potential Mitigations

• For outbound authentication: store passwords, keys, and other credentials outside of the code in a strongly-protected, encrypted configuration file or database that is protected from access by all outsiders, including other local users on the same system. Properly protect the key (CWE-320). If you cannot use encryption to protect the file, then make sure that the permissions are as restrictive as possible [REF-7].
• In Windows environments, the Encrypted File System (EFS) may provide some protection.
• For inbound authentication using passwords: apply strong one-way hashes to passwords and store those hashes in a configuration file or database with appropriate access control. That way, theft of the file/database still requires the attacker to try to crack the password. When handling an incoming password during authentication, take the hash of the password and compare it to the saved hash.
• Use randomly assigned salts for each separate hash that is generated. This increases the amount of computation that an attacker needs to conduct a brute-force attack, possibly limiting the effectiveness of the rainbow table method.
• For front-end to back-end connections: Three solutions are possible, although none are complete.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/191.html
• https://cwe.mitre.org/data/definitions/70.html

References

• http://www.securitytracker.com/id/1038904
• https://kb.juniper.net/JSA10791