Medium
Security advisory
An issue was discovered in Arm Mbed TLS before 2.23.0. Because of a side channel in modular exponentiation, an RSA private key used in a secure enclave could be disclosed.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2020-36421
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 11:27 UTC · Revision 1
Source evidence
An issue was discovered in Arm Mbed TLS before 2.23.0. Because of a side channel in modular exponentiation, an RSA private key used in a secure enclave could be disclosed.
osv:CVE-2020-36421
Complete source record
{
"id": "c4b1c606aec2c59a8192b44fe06a11d1c46b6e8ce90c85b8ad696ae66a4ea89d",
"url": "https://osv.dev/vulnerability/CVE-2020-36421",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2020-36421",
"summary": "An issue was discovered in Arm Mbed TLS before 2.23.0. Because of a side channel in modular exponentiation, an RSA private key used in a secure enclave could be disclosed.",
"evidence": "osv:CVE-2020-36421",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2020-36421",
"aliases": [
"CVE-2020-36421"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/Mbed-TLS/mbedtls",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "abc460236f17be148036e2c7e07e6a05f938b656"
},
{
"introduced": "3f8d78411a26e833db18d9fbde0e2f0baeda87f0"
},
{
"fixed": "3ede1737dc471199bf8d5d3824ee2545c11a497e"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "2.16.7"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "2.17.0"
},
{
"fixed": "2.23.0"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"mbedtls-2.19.1",
"mbedtls-2.16.6",
"mbedtls-2.22.0d0",
"mbedtls-2.16.5",
"mbedtls-2.21.0",
"mbedtls-2.20.0",
"mbedtls-2.16.4",
"mbedtls-2.20.0d0",
"mbedtls-2.16.3",
"mbedtls-2.19.0d2",
"mbedtls-2.19.0",
"mbedtls-2.19.0d1",
"mbedtls-2.16.2",
"mbedtls-2.16.0",
"mbedtls-2.14.0",
"mbedtls-2.13.1",
"mbedtls-2.13.0",
"mbedtls-2.12.0",
"mbedtls-2.11.0",
"mbedtls-2.10.0",
"mbedtls-2.7.0",
"mbedtls-2.9.0",
"mbedtls-2.8.0",
"mbedtls-2.8.0-rc1",
"mbedtls-2.7.0-rc1",
"mbedtls-2.6.0",
"mbedtls-2.6.0-rc1",
"mbedtls-2.5.1",
"mbedtls-2.5.0",
"mbedtls-2.4.0",
"mbedtls-2.2.1",
"yotta-2.3.1",
"mbedtls-2.3.0",
"mbedtls-2.2.0",
"mbedos-release-15-11",
"mbedos-techcon-oob2",
"mbedtls-2.1.2",
"mbedtls-2.1.0",
"mbedtls-2.1.1",
"beta-oob-2",
"mbedtls-2.0.0",
"polarssl-1.3.9",
"polarssl-1.3.8",
"polarssl-1.3.7",
"polarssl-1.3.6",
"polarssl-1.3.5",
"polarssl-1.3.4",
"polarssl-1.3.3",
"polarssl-1.3.2",
"polarssl-1.3.1",
"polarssl-1.3.0",
"polarssl-1.3.0-rc0",
"polarssl-1.2.6",
"polarssl-1.2.5",
"polarssl-1.2.4",
"polarssl-1.2.2",
"polarssl-1.2.1",
"polarssl-1.2.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-36421.json"
}
},
{
"ranges": [
{
"repo": "https://github.com/mbed-tls/mbedtls",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "abc460236f17be148036e2c7e07e6a05f938b656"
},
{
"fixed": "3ede1737dc471199bf8d5d3824ee2545c11a497e"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"fixed": "abc460236f17be148036e2c7e07e6a05f938b656"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v2.16.7"
},
{
"range": [
{
"fixed": "3ede1737dc471199bf8d5d3824ee2545c11a497e"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v2.23.0"
}
]
}
}
],
"versions": [
"mbedtls-2.19.1",
"mbedtls-2.16.6",
"mbedtls-2.22.0d0",
"mbedtls-2.16.5",
"mbedtls-2.21.0",
"mbedtls-2.20.0",
"mbedtls-2.16.4",
"mbedtls-2.20.0d0",
"mbedtls-2.16.3",
"mbedtls-2.19.0d2",
"mbedtls-2.19.0",
"mbedtls-2.19.0d1",
"mbedtls-2.16.2",
"mbedtls-2.16.0",
"mbedtls-2.14.0",
"mbedtls-2.13.1",
"mbedtls-2.13.0",
"mbedtls-2.12.0",
"mbedtls-2.11.0",
"mbedtls-2.10.0",
"mbedtls-2.7.0",
"mbedtls-2.9.0",
"mbedtls-2.8.0",
"mbedtls-2.8.0-rc1",
"mbedtls-2.7.0-rc1",
"mbedtls-2.6.0",
"mbedtls-2.6.0-rc1",
"mbedtls-2.5.1",
"mbedtls-2.5.0",
"mbedtls-2.4.0",
"mbedtls-2.2.1",
"yotta-2.3.1",
"mbedtls-2.3.0",
"mbedtls-2.2.0",
"mbedos-release-15-11",
"mbedos-techcon-oob2",
"mbedtls-2.1.2",
"mbedtls-2.1.0",
"mbedtls-2.1.1",
"beta-oob-2",
"mbedtls-2.0.0",
"polarssl-1.3.9",
"polarssl-1.3.8",
"polarssl-1.3.7",
"polarssl-1.3.6",
"polarssl-1.3.5",
"polarssl-1.3.4",
"polarssl-1.3.3",
"polarssl-1.3.2",
"polarssl-1.3.1",
"polarssl-1.3.0",
"polarssl-1.3.0-rc0",
"polarssl-1.2.6",
"polarssl-1.2.5",
"polarssl-1.2.4",
"polarssl-1.2.2",
"polarssl-1.2.1",
"polarssl-1.2.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-36421.json"
}
}
],
"modified": "2026-10-20T10:54:21.090011267Z",
"provider": "osv",
"references": [
"https://github.com/ARMmbed/mbedtls/releases/tag/v2.16.7",
"https://github.com/ARMmbed/mbedtls/releases/tag/v2.23.0",
"https://lists.debian.org/debian-lts-announce/2022/12/msg00036.html",
"https://github.com/ARMmbed/mbedtls/issues/3394",
"https://bugs.gentoo.org/730752"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*"
],
"vendor_product": "debian:debian_linux",
"extracted_events": [
{
"range": [
{
"introduced": "10.0"
},
{
"last_affected": "10.0"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2020-36421",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 385135,
"published_at": "2021-07-19T17:15:11.133+00:00"
}