High
mbedtls — security advisory
ARM mbedTLS version 2.7.0 and earlier contains a Ciphersuite Allows Incorrectly Signed Certificates vulnerability in mbedtls_ssl_get_verify_result() that can result in ECDSA-signed certificates are accepted, when only RSA-signed ones should be.. This attack appear to be exploitable via Peers negotiate a TLS-ECDH-RSA-* ciphersuite. Any of the peers can then provide an ECDSA-signed certificate, when only an RSA-signed one should be accepted..
- Products
- mbedtls
- Affected versions
- 2.1.2-1, 2.16.11-0.1ubuntu1, 2.16.11-0.3, 2.16.2-1, 2.16.3-1, 2.16.4-1ubuntu2, 2.16.4-1ubuntu2+esm1, 2.16.9-0.1ubuntu1, 2.2.0-1, 2.2.1-1, 2.2.1-2, 2.2.1-2ubuntu0.1, 2.2.1-2ubuntu0.2, 2.2.1-2ubuntu0.3, 2.28.0-1, 2.28.0-1build1, 2.28.0-1ubuntu0.1~esm1, 2.28.3-1, 2.28.6-1ubuntu1, 2.28.7-1.1ubuntu1, 2.28.7-1ubuntu1, 2.28.8-1, 2.28.8-1ubuntu0.1~esm1, 2.5.1-1ubuntu1, 2.6.0-1, 2.7.0-2, 2.8.0-1, 2.8.0-1ubuntu0.1~esm1, 3.6.2-3ubuntu1, 3.6.5-0.1ubuntu1, 3.6.5-0.1ubuntu2, 3.6.6-0.1ubuntu1, 3.6.7-3ubuntu1
- Fixed versions
- Not specified
- CVEs
- CVE-2018-1000520
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 00:22 UTC · Revision 1
Source evidence
ARM mbedTLS version 2.7.0 and earlier contains a Ciphersuite Allows Incorrectly Signed Certificates vulnerability in mbedtls_ssl_get_verify_result() that can result in ECDSA-signed certificates are accepted, when only RSA-signed ones should be.. This attack appear to be exploitable via Peers negotiate a TLS-ECDH-RSA-* ciphersuite. Any of the peers can then provide an ECDSA-signed certificate, when only an RSA-signed one should be accepted..
osv:UBUNTU-CVE-2018-1000520
mbedtls
Fixed versions: Not specified
mbedtls
Fixed versions: Not specified
mbedtls
Fixed versions: Not specified
mbedtls
Fixed versions: Not specified
mbedtls
Fixed versions: Not specified
mbedtls
Fixed versions: Not specified
mbedtls
Fixed versions: Not specified
mbedtls
Fixed versions: Not specified
Complete source record
{
"id": "2cccebe2b2a773b016aac8c114ee12e91127da5bb64ca639093bf893bd5fa027",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2018-1000520",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2018-1000520",
"summary": "ARM mbedTLS version 2.7.0 and earlier contains a Ciphersuite Allows Incorrectly Signed Certificates vulnerability in mbedtls_ssl_get_verify_result() that can result in ECDSA-signed certificates are accepted, when only RSA-signed ones should be.. This attack appear to be exploitable via Peers negotiate a TLS-ECDH-RSA-* ciphersuite. Any of the peers can then provide an ECDSA-signed certificate, when only an RSA-signed one should be accepted..",
"evidence": "osv:UBUNTU-CVE-2018-1000520",
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{
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},
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{
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{
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{
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{
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{
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{
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{
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"evidence": "/affected/4/versions"
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{
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"evidence": "/affected/4/versions"
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{
"value": "2.28.8-1",
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{
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{
"name": {
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"evidence": "/affected/5/package/name"
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{
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"evidence": "/affected/6/versions"
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"evidence": "/affected/6/versions"
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{
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"evidence": "/affected/6/versions"
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},
{
"name": {
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"evidence": "/affected/7/package/name"
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"evidence": "/affected/7/versions"
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{
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"evidence": "/affected/7/versions"
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{
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"evidence": "/affected/7/versions"
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],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2018-1000520",
"aliases": [
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],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
},
{
"type": "Ubuntu",
"score": "low"
}
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"affected": [
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"type": "ECOSYSTEM",
"events": [
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}
],
"package": {
"name": "mbedtls",
"purl": "pkg:deb/ubuntu/mbedtls?arch=source&distro=xenial",
"ecosystem": "Ubuntu:16.04:LTS"
},
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"2.2.1-2ubuntu0.2",
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],
"database_specific": {
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"ecosystem_specific": {
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"binary_name": "libmbedtls10",
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{
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"package": {
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"package": {
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"ecosystem": "Ubuntu:Pro:20.04:LTS"
},
"versions": [
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"2.16.3-1",
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],
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},
"ecosystem_specific": {
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{
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},
{
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"package": {
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"ecosystem_specific": {
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},
"ecosystem_specific": {
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},
{
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"ecosystem": "Ubuntu:26.10"
},
"versions": [
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},
"ecosystem_specific": {
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{
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},
{
"binary_name": "libmbedtls21",
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},
{
"binary_name": "libmbedx509-7",
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}
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},
{
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],
"package": {
"name": "mbedtls",
"purl": "pkg:deb/ubuntu/mbedtls?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"3.6.2-3ubuntu1",
"3.6.5-0.1ubuntu1",
"3.6.5-0.1ubuntu2"
],
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},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libmbedcrypto16",
"binary_version": "3.6.5-0.1ubuntu2"
},
{
"binary_name": "libmbedtls21",
"binary_version": "3.6.5-0.1ubuntu2"
},
{
"binary_name": "libmbedx509-7",
"binary_version": "3.6.5-0.1ubuntu2"
}
]
}
}
],
"modified": "2026-10-17T12:53:22.563511543Z",
"provider": "osv",
"upstream": [
"CVE-2018-1000520"
],
"references": [
"https://ubuntu.com/security/CVE-2018-1000520",
"https://github.com/ARMmbed/mbedtls/issues/1561",
"https://www.cve.org/CVERecord?id=CVE-2018-1000520"
]
},
"related_cves": [
{
"value": "CVE-2018-1000520",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 353428,
"published_at": "2018-06-26T16:29:00+00:00"
}