ECDSA remote timing attack

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).

Scores

EPSS (exploitation in 30 days)

1.1% · top 33% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.7.

Weakness

• Timing side channel

Affected products

• OpenSSL · OpenSSL

  • affected Fixed in OpenSSL 1.1.1d (Affected 1.1.1-1.1.1c)
  • affected Fixed in OpenSSL 1.1.0l (Affected 1.1.0-1.1.0k)
  • affected Fixed in OpenSSL 1.0.2t (Affected 1.0.2-1.0.2s)

References (35)

• 20190912 [slackware-security] openssl (SSA:2019-254-03) (opens in a new tab)mailing-listx_transferred
• openSUSE-SU-2019:2158 (opens in a new tab)vendor-advisoryx_transferred
• FEDORA-2019-d15aac6c4e (opens in a new tab)vendor-advisoryx_transferred
• openSUSE-SU-2019:2189 (opens in a new tab)vendor-advisoryx_transferred
• [debian-lts-announce] 20190925 [SECURITY] [DLA 1932-1] openssl security update (opens in a new tab)mailing-listx_transferred
• FEDORA-2019-d51641f152 (opens in a new tab)vendor-advisoryx_transferred
• 20191001 [SECURITY] [DSA 4539-1] openssl security update (opens in a new tab)mailing-listx_transferred
• 20191001 [SECURITY] [DSA 4540-1] openssl1.0 security update (opens in a new tab)mailing-listx_transferred
• DSA-4539 (opens in a new tab)vendor-advisoryx_transferred
• DSA-4540 (opens in a new tab)vendor-advisoryx_transferred
• openSUSE-SU-2019:2268 (opens in a new tab)vendor-advisoryx_transferred
• openSUSE-SU-2019:2269 (opens in a new tab)vendor-advisoryx_transferred
• GLSA-201911-04 (opens in a new tab)vendor-advisoryx_transferred
• USN-4376-1 (opens in a new tab)vendor-advisoryx_transferred
• https://www.oracle.com/security-alerts/cpuapr2020.html (opens in a new tab)x_transferred
• https://www.oracle.com/security-alerts/cpujul2020.html (opens in a new tab)x_transferred
• https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html (opens in a new tab)x_transferred
• https://www.tenable.com/security/tns-2019-08 (opens in a new tab)x_transferred
• https://www.oracle.com/security-alerts/cpujan2020.html (opens in a new tab)x_transferred
• https://www.openssl.org/news/secadv/20190910.txt (opens in a new tab)x_transferred
• https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=30c22fa8b1d840036b8e203585738df62a03cec8 (opens in a new tab)x_transferred
• https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=7c1709c2da5414f5b6133d00a03fc8c5bf996c7a (opens in a new tab)x_transferred
• https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=21c856b75d81eff61aa63b4f036bb64a85bf6d46 (opens in a new tab)x_transferred
• https://arxiv.org/abs/1909.01785 (opens in a new tab)x_transferred
• http://packetstormsecurity.com/files/154467/Slackware-Security-Advisory-openssl-Updates.html (opens in a new tab)x_transferred
• https://security.netapp.com/advisory/ntap-20190919-0002/ (opens in a new tab)x_transferred
• https://support.f5.com/csp/article/K73422160?utm_source=f5support&amp%3Butm_medium=RSS (opens in a new tab)x_transferred
• https://www.tenable.com/security/tns-2019-09 (opens in a new tab)x_transferred
• https://security.netapp.com/advisory/ntap-20200122-0002/ (opens in a new tab)x_transferred
• https://security.netapp.com/advisory/ntap-20200416-0003/ (opens in a new tab)x_transferred
• USN-4376-2 (opens in a new tab)vendor-advisoryx_transferred
• USN-4504-1 (opens in a new tab)vendor-advisoryx_transferred
• https://www.oracle.com/security-alerts/cpuoct2020.html (opens in a new tab)x_transferred
• https://kc.mcafee.com/corporate/index?page=content&id=SB10365 (opens in a new tab)x_transferred
• https://security.netapp.com/advisory/ntap-20240621-0006/ (opens in a new tab)x_transferred

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2019-1547](https://trackcve.app/badge/CVE-2019-1547.svg)](https://trackcve.app/cve/CVE-2019-1547)

Record last updated 16 Sept 2024, 16:33 UTC.