# CVE-2019-1547: ECDSA remote timing attack

> Attackers can recover ECDSA private keys via timing attacks when applications use explicit curve parameters without cofactors in OpenSSL.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Sep 2019
- **Updated:** 16 Sep 2024
- **Also known as:** ALPINE-CVE-2019-1547, CLEANSTART-2026-TP50755, DEBIAN-CVE-2019-1547, GHSA-q2qv-648h-wcqp, JLSEC-2026-214, UBUNTU-CVE-2019-1547

## What is CVE-2019-1547?

CVE-2019-1547 is a medium-severity vulnerability in Openssl Openssl, published on 10 Sep 2019. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Normally in OpenSSL EC groups always have a co-factor present and this is used in side channel resistant code paths. However, in some cases, it is possible to construct a group using explicit parameters (instead of using a named curve). In those cases it is possible that such a group does not have the cofactor present. This can occur even where all the parameters match a known named curve. If such a curve is used then OpenSSL falls back to non-side channel resistant code paths which may result in full key recovery during an ECDSA signature operation. In order to be vulnerable an attacker would have to have the ability to time the creation of a large number of signatures where explicit parameters with no co-factor present are in use by an application using libcrypto. For the avoidance of doubt libssl is not vulnerable because explicit parameters are never used. Fixed in OpenSSL 1.1.1d (Affected 1.1.1-1.1.1c). Fixed in OpenSSL 1.1.0l (Affected 1.1.0-1.1.0k). Fixed in OpenSSL 1.0.2t (Affected 1.0.2-1.0.2s).

## Which versions are affected by CVE-2019-1547?

It affects 1 product.


Products: Openssl Openssl.

## How do I fix CVE-2019-1547?

Upgrade to a fixed version.

## Is CVE-2019-1547 being exploited?

There is no known exploitation of CVE-2019-1547 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-2019-1547 and fix it if it is affected.

What it is: CVE-2019-1547 is a medium-severity vulnerability in Openssl Openssl, published on 10 Sep 2019. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-1547 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-2019-1547/ (Markdown: https://insights.sbomify.com/CVE-2019-1547/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-1547
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-1547
- OSV: https://osv.dev/vulnerability/CVE-2019-1547

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-1547/
Summaries are generated and may contain mistakes; the official description above is the record.