openssl — security advisory
Issue summary: Checking excessively long DH keys or parameters may be very slow. Impact summary: Applications that use the functions DH_check(), DH_check_ex() or EVP_PKEY_param_check() to check a DH key or DH parameters may experience long delays. Where the key or parameters that are being checked have been obtained from an untrusted source this may lead to a Denial of Service. The function DH_check() performs various checks on DH parameters. After fixing CVE-2023-3446 it was discovered that a large q parameter value can also trigger an overly long computation during some of these checks. A correct q value, if present, cannot be larger than the modulus p parameter, thus it is unnecessary to perform these checks if q is larger than p. An application that calls DH_check() and supplies a key or parameters obtained from an untrusted source could be vulnerable to a Denial of Service attack. The function DH_check() is itself called by a number of other OpenSSL functions. An application calling any of those other functions may similarly be affected. The other functions affected by this are DH_check_ex() and EVP_PKEY_param_check(). Also vulnerable are the OpenSSL dhparam and pkeyparam command line applications when using the "-check" option. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue.
- Products
- openssl
- Affected versions
- 3.0.9-1
- Fixed versions
- 3.0.10-1, 3.0.10-1~deb12u1
- CVEs
- CVE-2023-3817
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 16:04 UTC · Revision 1
Source evidence
Issue summary: Checking excessively long DH keys or parameters may be very slow. Impact summary: Applications that use the functions DH_check(), DH_check_ex() or EVP_PKEY_param_check() to check a DH key or DH parameters may experience long delays. Where the key or parameters that are being checked have been obtained from an untrusted source this may lead to a Denial of Service. The function DH_check() performs various checks on DH parameters. After fixing CVE-2023-3446 it was discovered that a large q parameter value can also trigger an overly long computation during some of these checks. A correct q value, if present, cannot be larger than the modulus p parameter, thus it is unnecessary to perform these checks if q is larger than p. An application that calls DH_check() and supplies a key or parameters obtained from an untrusted source could be vulnerable to a Denial of Service attack. The function DH_check() is itself called by a number of other OpenSSL functions. An application calling any of those other functions may similarly be affected. The other functions affected by this are DH_check_ex() and EVP_PKEY_param_check(). Also vulnerable are the OpenSSL dhparam and pkeyparam command line applications when using the "-check" option. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue.
osv:DEBIAN-CVE-2023-3817
openssl
Fixed versions: 3.0.10-1~deb12u1
openssl
Fixed versions: 3.0.10-1
openssl
Fixed versions: 3.0.10-1
Complete source record
{
"id": "2bc273bad2d1b919b602d2285481679162eaef866b53ca972e51044ffc2ab702",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2023-3817",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2023-3817",
"summary": "Issue summary: Checking excessively long DH keys or parameters may be very slow. Impact summary: Applications that use the functions DH_check(), DH_check_ex() or EVP_PKEY_param_check() to check a DH key or DH parameters may experience long delays. Where the key or parameters that are being checked have been obtained from an untrusted source this may lead to a Denial of Service. The function DH_check() performs various checks on DH parameters. After fixing CVE-2023-3446 it was discovered that a large q parameter value can also trigger an overly long computation during some of these checks. A correct q value, if present, cannot be larger than the modulus p parameter, thus it is unnecessary to perform these checks if q is larger than p. An application that calls DH_check() and supplies a key or parameters obtained from an untrusted source could be vulnerable to a Denial of Service attack. The function DH_check() is itself called by a number of other OpenSSL functions. An application calling any of those other functions may similarly be affected. The other functions affected by this are DH_check_ex() and EVP_PKEY_param_check(). Also vulnerable are the OpenSSL dhparam and pkeyparam command line applications when using the \"-check\" option. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue.",
"evidence": "osv:DEBIAN-CVE-2023-3817",
"products": [
{
"name": {
"value": "openssl",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "3.0.10-1~deb12u1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
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"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "openssl",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
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"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
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},
"prerequisites": [],
"fixed_versions": [
{
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}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2023-3817",
"aliases": [
"DEBIAN-CVE-2023-3817"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.0.10-1~deb12u1"
}
]
}
],
"package": {
"name": "openssl",
"purl": "pkg:deb/debian/openssl?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"3.0.9-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-3817.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.0.10-1"
}
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],
"package": {
"name": "openssl",
"purl": "pkg:deb/debian/openssl?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-3817.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.0.10-1"
}
]
}
],
"package": {
"name": "openssl",
"purl": "pkg:deb/debian/openssl?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-3817.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-26T18:02:40.853119363Z",
"provider": "osv",
"upstream": [
"CVE-2023-3817"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2023-3817"
]
},
"related_cves": [
{
"value": "CVE-2023-3817",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 456574,
"published_at": "2023-07-31T16:15:10.497+00:00"
}