CVE-2020-20949 : Exploit Details and Defense Strategies
Learn about CVE-2020-20949, a vulnerability in STM32Cube's cryptographic firmware library software expansion that allows decryption of encrypted data, leading to remote information disclosure. Find mitigation steps and long-term security practices here.
Bleichenbacher's attack on PKCS #1 v1.5 padding for RSA in STM32 cryptographic firmware library software expansion for STM32Cube (UM1924) can lead to remote information disclosure.
Understanding CVE-2020-20949
What is CVE-2020-20949?
Bleichenbacher's attack on PKCS #1 v1.5 padding for RSA in STM32Cube's cryptographic firmware library software expansion exposes a vulnerability that allows decryption of encrypted data through successive queries.
The Impact of CVE-2020-20949
The vulnerability enables attackers to decrypt encrypted ciphertext, leading to remote information disclosure.
Technical Details of CVE-2020-20949
Vulnerability Description
The vulnerability arises from the improper implementation of PKCS #1 v1.5 padding in the STM32 cryptographic firmware library software expansion for STM32Cube (UM1924).
Affected Systems and Versions
- Product: n/a
- Vendor: n/a
- Version: n/a
Exploitation Mechanism
Attackers can exploit Bleichenbacher's oracle attack by making successive queries to the server using the vulnerable library to decrypt encrypted data.
Mitigation and Prevention
Immediate Steps to Take
- Disable or restrict access to the vulnerable library
- Implement network-level security controls
- Monitor and analyze network traffic for suspicious activities
Long-Term Security Practices
- Regularly update cryptographic libraries and firmware
- Conduct security assessments and penetration testing
- Educate developers on secure coding practices
Patching and Updates
Apply patches and updates provided by STM32Cube to address the vulnerability.