Vulnerabilities > CVE-2022-30316 - Improper Validation of Integrity Check Value vulnerability in Honeywell Safety Manager Firmware
Summary
Honeywell Experion PKS Safety Manager 5.02 has Insufficient Verification of Data Authenticity. According to FSCT-2022-0054, there is a Honeywell Experion PKS Safety Manager unauthenticated firmware update issue. The affected components are characterized as: Firmware update functionality. The potential impact is: Firmware manipulation. The Honeywell Experion PKS Safety Manager utilizes the DCOM-232/485 communication FTA serial interface and Enea POLO bootloader for firmware management purposes. An engineering workstation running the Safety Builder software communicates via serial or serial-over-ethernet link with the DCOM-232/485 interface. Firmware images were found to have no authentication (in the form of firmware signing) and only relied on insecure checksums for regular integrity checks. Firmware images are unsigned. An attacker with access to the serial interface (either through physical access, a compromised EWS or an exposed serial-to-ethernet gateway) can utilize hardcoded credentials (see FSCT-2022-0052) for the POLO bootloader to control the boot process and push malicious firmware images to the controller allowing for firmware manipulation, remote code execution and denial of service impacts. A mitigating factor is that in order for a firmware update to be initiated, the Safety Manager has to be rebooted which is typically done by means of physical controls on the Safety Manager itself. As such, an attacker would have to either lay dormant until a legitimate reboot occurs or possibly attempt to force a reboot through a secondary vulnerability.
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| OS | 1 | |
| Hardware | 1 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Padding Oracle Crypto Attack An attacker is able to efficiently decrypt data without knowing the decryption key if a target system leaks data on whether or not a padding error happened while decrypting the ciphertext. A target system that leaks this type of information becomes the padding oracle and an attacker is able to make use of that oracle to efficiently decrypt data without knowing the decryption key by issuing on average 128*b calls to the padding oracle (where b is the number of bytes in the ciphertext block). In addition to performing decryption, an attacker is also able to produce valid ciphertexts (i.e., perform encryption) by using the padding oracle, all without knowing the encryption key. Any cryptosystem can be vulnerable to padding oracle attacks if the encrypted messages are not authenticated to ensure their validity prior to decryption, and then the information about padding error is leaked to the attacker. This attack technique may be used, for instance, to break CAPTCHA systems or decrypt/modify state information stored in client side objects (e.g., hidden fields or cookies). This attack technique is a side-channel attack on the cryptosystem that uses a data leak from an improperly implemented decryption routine to completely subvert the cryptosystem. The one bit of information that tells the attacker whether a padding error during decryption has occurred, in whatever form it comes, is sufficient for the attacker to break the cryptosystem. That bit of information can come in a form of an explicit error message about a padding error, a returned blank page, or even the server taking longer to respond (a timing attack). This attack can be launched cross domain where an attacker is able to use cross-domain information leaks to get the bits of information from the padding oracle from a target system / service with which the victim is communicating. To do so an attacker sends a request containing ciphertext to the target system. Due to the browser's same origin policy, the attacker is not able to see the response directly, but can use cross-domain information leak techniques to still get the information needed (i.e., information on whether or not a padding error has occurred). For instance, this can be done using "img" tag plus the onerror()/onload() events. The attacker's JavaScript can make web browsers to load an image on the target site, and know if the image is loaded or not. This is 1-bit information needed for the padding oracle attack to work: if the image is loaded, then it is valid padding, otherwise it is not.
- Manipulating Writeable Configuration Files Generally these are manually edited files that are not in the preview of the system administrators, any ability on the attackers' behalf to modify these files, for example in a CVS repository, gives unauthorized access directly to the application, the same as authorized users.