CVE-2020-36475
published 2021-08-23CVE-2020-36475: An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). The calculations performed by mbedtls_mpi_exp_mod are not…
PriorityP337high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
1.97%
77.9th percentile
An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). The calculations performed by mbedtls_mpi_exp_mod are not limited; thus, supplying overly large parameters could lead to denial of service when generating Diffie-Hellman key pairs.
Affected
14 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| arm | mbed_tls | < 2.7.18 | 2.7.18 |
| arm | mbed_tls | >= 2.17.0 < 2.25.0 | 2.25.0 |
| arm | mbed_tls | >= 2.8.0 < 2.16.9 | 2.16.9 |
| debian | debian_linux | — | — |
| debian | debian_linux | — | — |
| debian | mbedtls | < mbedtls 2.16.9-0.1 (bookworm) | mbedtls 2.16.9-0.1 (bookworm) |
| mbed | mbedtls | >= 0 < 2.16.9-0.1 | 2.16.9-0.1 |
| mbed | mbedtls | >= 0 < 2.16.9-0.1 | 2.16.9-0.1 |
| mbed | mbedtls | >= 0 < 2.16.9-0.1 | 2.16.9-0.1 |
| mbed | mbedtls | >= 0 < 2.16.9-0.1 | 2.16.9-0.1 |
| msrc | azl3_qemu_8.2.0-16_on_azure_linux_3.0 | — | — |
| msrc | cbl2_qemu_6.2.0-24_on_cbl_mariner_2.0 | — | — |
| siemens | logo_!_cmr2020_firmware | < 2.2 | 2.2 |
| siemens | logo_!_cmr2040_firmware | < 2.2 | 2.2 |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvdv2.05.0MEDIUMAV:N/AC:L/Au:N/C:N/I:N/A:P
osv7.5HIGH
vendor_debian7.5HIGH
vendor_msrc7.5HIGH
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CISA ICS
Siemens LOGO! CMR and SIMATIC RTU 3000
cisa_ics·2021-09-14·CVSS 7.5
[HIGH] Siemens LOGO! CMR and SIMATIC RTU 3000
## Archived Content In an effort to keep CISA.gov current, the archive contains outdated information that may not reflect current policy or programs.
ICS Advisory
##
Siemens LOGO! CMR and SIMATIC RTU 3000
Last RevisedSeptember 14, 2021
Alert CodeICSA-21-257-20
## 1. EXECUTIVE SUMMARY
- CVSS v3 7.5
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Siemens
- Equipment: LOGO! CMR2020, LOGO! CMR2040 and SIMATIC RTU 3000 family
- Vulnerabilities: Incorrect Calculation of Buffer Size, Improper Certificate Validation
## 2. RISK EVALUATION
Successful exploitation of these vulnerabilities could allow an attacker with access to any of the interfaces of an affected device to impact the availability or to communicate with invalid c
Microsoft
An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). The calculations performed by mbedtls_mpi_exp_mod are not limited; thus, supplying overly large paramet
vendor_msrc·2021-08-10·CVSS 7.5
CVE-2020-36475 [HIGH] CWE-131 An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). The calculations performed by mbedtls_mpi_exp_mod are not limited; thus, supplying overly large paramet
An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). The calculations performed by mbedtls_mpi_exp_mod are not limited; thus, supplying overly large parameters could lead to denial of service when generating Diffie-Hellman key pairs.
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more in
Debian
CVE-2020-36475: mbedtls - An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and bef...
vendor_debian·2020·CVSS 7.5
CVE-2020-36475 [HIGH] CVE-2020-36475: mbedtls - An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and bef...
An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). The calculations performed by mbedtls_mpi_exp_mod are not limited; thus, supplying overly large parameters could lead to denial of service when generating Diffie-Hellman key pairs.
Scope: local
bookworm: resolved (fixed in 2.16.9-0.1)
bullseye: resolved (fixed in 2.16.9-0.1)
forky: resolved (fixed in 2.16.9-0.1)
sid: resolved (fixed in 2.16.9-0.1)
trixie: resolved (fixed in 2.16.9-0.1)
GHSA
GHSA-7qm6-rr75-xc68: An issue was discovered in Mbed TLS before 2
ghsa_unreviewed·2022-05-24
CVE-2020-36475 [HIGH] CWE-131 GHSA-7qm6-rr75-xc68: An issue was discovered in Mbed TLS before 2
An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). The calculations performed by mbedtls_mpi_exp_mod are not limited; thus, supplying overly large parameters could lead to denial of service when generating Diffie-Hellman key pairs.
OSV
CVE-2020-36475: An issue was discovered in Mbed TLS before 2
osv·2021-08-23·CVSS 7.5
CVE-2020-36475 [HIGH] CVE-2020-36475: An issue was discovered in Mbed TLS before 2
An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). The calculations performed by mbedtls_mpi_exp_mod are not limited; thus, supplying overly large parameters could lead to denial of service when generating Diffie-Hellman key pairs.
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
https://cert-portal.siemens.com/productcert/pdf/ssa-756638.pdfhttps://github.com/ARMmbed/mbedtls/releases/tag/v2.16.9https://github.com/ARMmbed/mbedtls/releases/tag/v2.25.0https://github.com/ARMmbed/mbedtls/releases/tag/v2.7.18https://lists.debian.org/debian-lts-announce/2021/11/msg00021.htmlhttps://lists.debian.org/debian-lts-announce/2022/12/msg00036.htmlhttps://cert-portal.siemens.com/productcert/pdf/ssa-756638.pdfhttps://github.com/ARMmbed/mbedtls/releases/tag/v2.16.9https://github.com/ARMmbed/mbedtls/releases/tag/v2.25.0https://github.com/ARMmbed/mbedtls/releases/tag/v2.7.18https://lists.debian.org/debian-lts-announce/2021/11/msg00021.htmlhttps://lists.debian.org/debian-lts-announce/2022/12/msg00036.html
2021-08-23
Published