Vulnerability Report

CVE-2020-20949

Title: St Stm32Cubeh7 Cryptographic Failures

Information Disclosure

Proof Of Concept

No public PoC currently indexed for CVE-2020-20949.

CWE Category CWE-327
Published Date Jan 20, 2021
Modified Date Jul 09, 2026
Exploit Status Not Found
Score 5.9 CVSS v3.1
Exploit Probability (EPSS)
0.92%

Vulnerability Summary

CVE-2020-20949: Bleichenbacher's attack on PKCS #1 v1.5 padding for RSA in STM32 cryptographic firmware library software expansion for STM32Cube (UM1924). The vulnerability can allow one to use Bleichenbacher's oracle attack to decrypt an encrypted ciphertext by making successive queries to the server using the vulnerable library, resulting in remote information disclosure.

Impacted Vendors

I
ietf 1
S
st 21

Reference Links

http://archiv.infsec.ethz.ch/education/fs08/secsem/bleichenbacher98.pdf http://st.com http://x-cube-cryptolib.com https://bi-zone.medium.com/silence-will-fall-or-how-it-can-take-2-years-to-get-your-vuln-registered-e6134846f5bb https://www.st.com/en/embedded-software/x-cube-cryptolib.html http://archiv.infsec.ethz.ch/education/fs08/secsem/bleichenbacher98.pdf http://st.com http://x-cube-cryptolib.com https://bi-zone.medium.com/silence-will-fall-or-how-it-can-take-2-years-to-get-your-vuln-registered-e6134846f5bb https://www.st.com/en/embedded-software/x-cube-cryptolib.html
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
5.9
Attack Vector
NETWORK
Complexity
HIGH
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v2.0
Source Entity [email protected]
Severity MEDIUM
4.3
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:N/AC:M/Au:N/C:P/I:N/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2020-20949 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity HIGH
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected Stack

No specific products linked.