High severity · published Aug 23, 2021
CVE-2020-36478
An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS)
7.5
CVSS
1.1%
EPSS
No
On KEV
Description
An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). A NULL algorithm parameters entry looks identical to an array of REAL (size zero) and thus the certificate is considered valid. However, if the parameters do not match in any way, then the certificate should be considered invalid.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.1% · higher than 66% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DL
Debian Linux · Debian
9.0; 10.0 · source: NVD
LC
Logo! Cmr2020 Firmware · Siemens
before 2.2 · source: NVD
LC
Logo! Cmr2040 Firmware · Siemens
before 2.2 · source: NVD
MT
Mbed Tls · Arm
before 2.7.18; 2.8.0 before 2.16.9; 2.17.0 before 2.25.0 · source: NVD
SR
Simatic Rtu3000c Firmware · Siemens
All versions, or not specified · source: NVD
SR
Simatic Rtu3030c Firmware · Siemens
All versions, or not specified · source: NVD
SR
Simatic Rtu3031c Firmware · Siemens
All versions, or not specified · source: NVD
SR
Simatic Rtu3041c Firmware · Siemens
All versions, or not specified · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-36478
CVE.org
https://www.cve.org/CVERecord?id=CVE-2020-36478
Patch
https://cert-portal.siemens.com/productcert/pdf/ssa-756638.pdf
Exploit
https://github.com/ARMmbed/mbedtls/issues/3629
Release Notes
https://github.com/ARMmbed/mbedtls/releases/tag/v2.16.9
Release Notes
https://github.com/ARMmbed/mbedtls/releases/tag/v2.25.0
Release Notes
https://github.com/ARMmbed/mbedtls/releases/tag/v2.7.18
Mailing List
https://lists.debian.org/debian-lts-announce/2021/11/msg00021.html
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