# CVE-2023-3817: Excessive time spent checking DH q parameter value > Attackers can cause denial of service by supplying large DH parameters to applications using OpenSSL's DH_check functions. - **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 31 Jul 2023 - **Updated:** 14 Oct 2026 - **Also known as:** ALPINE-CVE-2023-3817, AZL-27815, AZL-27817, AZL-31139, AZL-34669, AZL-35247, AZL-37764, CLEANSTART-2026-GH88733, CLSA-2023-1693418284, CLSA-2023-1693418632, CLSA-2023-1693419428, CLSA-2023-1693419971, DEBIAN-CVE-2023-3817, GHSA-c945-cqj5-wfv6, JLSEC-2026-241, OESA-2023-1481, SUSE-SU-2023:3239-1, SUSE-SU-2023:3242-1, SUSE-SU-2023:3243-1, SUSE-SU-2023:3244-1, SUSE-SU-2023:3244-2, SUSE-SU-2023:3291-1, SUSE-SU-2023:3291-2, SUSE-SU-2023:3308-1, SUSE-SU-2023:3338-1, SUSE-SU-2023:3339-1, SUSE-SU-2023:3397-1, SUSE-SU-2023:3958-1, UBUNTU-CVE-2023-3817, openSUSE-SU-2024:13090-1, openSUSE-SU-2024:13097-1, openSUSE-SU-2024:13111-1 ## What is CVE-2023-3817? CVE-2023-3817 is a medium-severity denial of service vulnerability in Openssl Openssl, published on 31 Jul 2023. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description 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. Weakness: CWE-834 (Excessive Iteration), CWE-606 (Unchecked Input for Loop Condition) ## Which versions are affected by CVE-2023-3817? It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `openssl-1_1` | SUSE:Enterprise Storage 7.1 | All versions | 1.1.1d-150200.11.75.1 | | `openssl-1_1` | SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSS | All versions | 1.1.0i-150100.14.65.6 | | `openssl-1_1` | SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS | All versions | 1.1.1d-150200.11.75.1 | | `openssl-1_1` | SUSE:Linux Enterprise High Performance Computing 15 SP3-ESPOS | All versions | 1.1.1d-150200.11.75.1 | | `openssl-1_1` | SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS | All versions | 1.1.1d-150200.11.75.1 | | `openssl-1_1` | SUSE:Linux Enterprise Micro 5.1 | All versions | 1.1.1d-150200.11.75.1 | | `openssl-1_1` | SUSE:Linux Enterprise Micro 5.2 | All versions | 1.1.1d-150200.11.75.1 | | `openssl-1_1` | SUSE:Linux Enterprise Micro 5.3 | All versions | 1.1.1l-150400.7.53.1 | | `openssl-3` | SUSE:Linux Enterprise Micro 5.3 | All versions | 3.0.8-150400.4.34.1 | | `openssl-1_1` | SUSE:Linux Enterprise Micro 5.4 | All versions | 1.1.1l-150400.7.53.1 | | `openssl-3` | SUSE:Linux Enterprise Micro 5.4 | All versions | 3.0.8-150400.4.34.1 | | `openssl-1_1` | SUSE:Linux Enterprise Module for Basesystem 15 SP4 | All versions | 1.1.1l-150400.7.53.1 | | `openssl-3` | SUSE:Linux Enterprise Module for Basesystem 15 SP4 | All versions | 3.0.8-150400.4.34.1 | | `openssl-1_1` | SUSE:Linux Enterprise Module for Basesystem 15 SP5 | All versions | 1.1.1l-150500.17.15.1 | | `openssl-3` | SUSE:Linux Enterprise Module for Basesystem 15 SP5 | All versions | 3.0.8-150500.5.11.1 | | `openssl-1_0_0` | SUSE:Linux Enterprise Module for Legacy 15 SP4 | All versions | 1.0.2p-150000.3.85.1 | | `openssl-1_0_0` | SUSE:Linux Enterprise Module for Legacy 15 SP5 | All versions | 1.0.2p-150000.3.85.1 | | `openssl` | SUSE:Linux Enterprise Server 12 SP2-BCL | All versions | 1.0.2j-60.104.1 | | `openssl-1_0_0` | SUSE:Linux Enterprise Server 12 SP5 | All versions | 1.0.2p-3.84.1 | | `openssl-1_1` | SUSE:Linux Enterprise Server 12 SP5 | All versions | 1.1.1d-2.98.1 | | `openssl-1_1` | SUSE:Linux Enterprise Server 15 SP1-LTSS | All versions | 1.1.0i-150100.14.65.6 | | `openssl-1_1` | SUSE:Linux Enterprise Server 15 SP2-LTSS | All versions | 1.1.1d-150200.11.75.1 | | `openssl-1_1` | SUSE:Linux Enterprise Server 15 SP3-LTSS | All versions | 1.1.1d-150200.11.75.1 | | `openssl-1_0_0` | SUSE:Linux Enterprise Server for SAP Applications 12 SP5 | All versions | 1.0.2p-3.84.1 | | `openssl-1_1` | SUSE:Linux Enterprise Server for SAP Applications 12 SP5 | All versions | 1.1.1d-2.98.1 | | `openssl-1_1` | SUSE:Linux Enterprise Server for SAP Applications 15 SP1 | All versions | 1.1.0i-150100.14.65.6 | | `openssl-1_1` | SUSE:Linux Enterprise Server for SAP Applications 15 SP2 | All versions | 1.1.1d-150200.11.75.1 | | `openssl-1_1` | SUSE:Linux Enterprise Server for SAP Applications 15 SP3 | All versions | 1.1.1d-150200.11.75.1 | | `openssl-1_0_0` | SUSE:Linux Enterprise Software Development Kit 12 SP5 | All versions | 1.0.2p-3.84.1 | | `openssl-1_1` | SUSE:Linux Enterprise Software Development Kit 12 SP5 | All versions | 1.1.1d-2.98.1 | | `openssl-1_1` | SUSE:Manager Proxy 4.2 | All versions | 1.1.1d-150200.11.75.1 | | `openssl-1_1` | SUSE:Manager Server 4.2 | All versions | 1.1.1d-150200.11.75.1 | | `openssl-1_0_0` | openSUSE:Leap 15.4 | All versions | 1.0.2p-150000.3.85.1 | | `openssl-1_1` | openSUSE:Leap 15.4 | All versions | 1.1.1l-150400.7.53.1 | | `openssl-3` | openSUSE:Leap 15.4 | All versions | 3.0.8-150400.4.34.1 | | `openssl-1_0_0` | openSUSE:Leap 15.5 | All versions | 1.0.2p-150000.3.85.1 | | `openssl-1_1` | openSUSE:Leap 15.5 | All versions | 1.1.1l-150500.17.15.1 | | `openssl-3` | openSUSE:Leap 15.5 | All versions | 3.0.8-150500.5.11.1 | | `openssl-1_1` | openSUSE:Leap Micro 5.3 | All versions | 1.1.1l-150400.7.53.1 | | `openssl-3` | openSUSE:Leap Micro 5.3 | All versions | 3.0.8-150400.4.34.1 | Products: Openssl Openssl. ## How do I fix CVE-2023-3817? Apply the vendor's patch. ## Is CVE-2023-3817 being exploited? There is no known exploitation of CVE-2023-3817 in the wild and no public exploit code. ## Other vulnerabilities in Openssl Openssl - [CVE-2009-3245](https://insights.sbomify.com/CVE-2009-3245/): Null dereference in n/a (critical 10.0) - [CVE-2006-3738](https://insights.sbomify.com/CVE-2006-3738/): Memory corruption in n/a (critical 10.0) - [CVE-2026-63073](https://insights.sbomify.com/CVE-2026-63073/): Untrusted Sender DN Used as Format String in CMP Response Validation (critical 9.8) - [CVE-2016-6309](https://insights.sbomify.com/CVE-2016-6309/): Use after free in n/a (critical 9.8) - [CVE-2016-0799](https://insights.sbomify.com/CVE-2016-0799/): Integer overflow in n/a (critical 9.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2023-3817 and fix it if it is affected. What it is: CVE-2023-3817 is a medium-severity denial of service vulnerability in Openssl Openssl, published on 31 Jul 2023. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2023-3817 in the wild and no public exploit code. Affected product: Openssl Openssl. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2023-3817/ (Markdown: https://insights.sbomify.com/CVE-2023-3817/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2023-3817 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-3817 - OSV: https://osv.dev/vulnerability/CVE-2023-3817 --- From sbomify Insights: https://insights.sbomify.com/CVE-2023-3817/ Summaries are generated and may contain mistakes; the official description above is the record.