Vulnerability Name:

CVE-2020-20950 (CCN-195234)

Assigned:2020-08-13
Published:2021-01-18
Updated:2021-07-21
Summary:Bleichenbacher's attack on PKCS #1 v1.5 padding for RSA in Microchip Libraries for Applications 2018-11-26 All up to 2018-11-26. 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.
CVSS v3 Severity:5.9 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N)
5.2 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:U/RC:R)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): None
Availibility (A): None
5.9 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N)
5.2 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:U/RC:R)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): None
Availibility (A): None
CVSS v2 Severity:4.3 Medium (CVSS v2 Vector: AV:N/AC:M/Au:N/C:P/I:N/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Medium
Authentication (Au): None
Impact Metrics:Confidentiality (C): Partial
Integrity (I): None
Availibility (A): None
5.4 Medium (CCN CVSS v2 Vector: AV:N/AC:H/Au:N/C:C/I:N/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): High
Athentication (Au): None
Impact Metrics:Confidentiality (C): Complete
Integrity (I): None
Availibility (A): None
Vulnerability Type:CWE-326
Vulnerability Consequences:Obtain Information
References:Source: MISC
Type: Technical Description, Third Party Advisory
http://archiv.infsec.ethz.ch/education/fs08/secsem/bleichenbacher98.pdf

Source: MITRE
Type: CNA
CVE-2020-20950

Source: MISC
Type: Product
http://microchip.com

Source: CCN
Type: Medium Web site
Silence Will Fall (Or How It Can Take 2 Years to Get Your Vuln Registered)

Source: MISC
Type: Technical Description, Third Party Advisory
https://bi-zone.medium.com/silence-will-fall-or-how-it-can-take-2-years-to-get-your-vuln-registered-e6134846f5bb

Source: XF
Type: UNKNOWN
microchip-cve202020950-info-disc(195234)

Source: CCN
Type: Microchip Web site
Microchip Libraries for Applications (MLA)

Source: MISC
Type: Product
https://www.microchip.com/mplab/microchip-libraries-for-applications

Vulnerable Configuration:Configuration 1:
  • cpe:/a:ietf:public_key_cryptography_standards_#1:1.5:*:*:*:*:*:*:*

  • Configuration 2:
  • cpe:/a:microchip:microchip_libraries_for_applications:*:*:*:*:*:*:*:* (Version <= 2018-11-26)
  • AND
  • cpe:/o:apple:mac_os:-:*:*:*:*:*:*:*
  • OR cpe:/o:linux:linux_kernel:-:*:*:*:*:*:*:*
  • OR cpe:/o:microsoft:windows:-:*:*:*:*:*:*:*

  • * Denotes that component is vulnerable
    BACK
    ietf public key cryptography standards #1 1.5
    microchip microchip libraries for applications *
    apple mac os -
    linux linux kernel -
    microsoft windows -