Vulnerability in Ietf Public Key Cryptography Standards \#1
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.
Vulnerability class: POODLE (CVE-2014-3566)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.009 (58.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 58.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000
Affected products
Weakness classification (CWE)
References
- archiv.infsec.ethz.ch/education/fs08/secsem/bleichenbacher98.pdf (Technical Description, Third Party Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Product)
- af854a3a-2127-422b-91ae-364da2661108 (Broken Link)
- www.st.com/en/embedded-software/x-cube-cryptolib.html (Third Party Advisory)
- bi-zone.medium.com/silence-will-fall-or-how-it-can-take-2-years-to-get-your-vul… (Technical Description, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-20949?
- CVE-2020-20949 is a medium-severity vulnerability in Ietf Public Key Cryptography Standards \#1, classified under Use of a Broken or Risky Cryptographic Algorithm. CVSS score: 5.9/10. Published 2021-01-20.
- How severe is CVE-2020-20949?
- Medium severity. CVSS v3 base score is 5.9 out of 10.