CVE-2015-4000
Improper Certificate Validation
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Description
The TLS protocol 1.2 and earlier, when a DHE_EXPORT ciphersuite is enabled on a server but not on a client, does not properly convey a DHE_EXPORT choice, which allows man-in-the-middle attackers to conduct cipher-downgrade attacks by rewriting a ClientHello with DHE replaced by DHE_EXPORT and then rewriting a ServerHello with DHE_EXPORT replaced by DHE, aka the "Logjam" issue.
Official description from the CVE record, published by mitre. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org
Key data
CVSS 3.1 Low 3.7
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: High
The attack depends on conditions outside the attacker's control, so it takes preparation.
Privileges required: None
No account or privileges are needed.
User interaction: None
No action from any user is needed.
Scope: Unchanged
The impact stays within the vulnerable component.
Confidentiality impact: None
No effect on the secrecy of data.
Integrity impact: Low
Limited effect on the trustworthiness of data.
Availability impact: None
No effect on availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | High | The attack depends on conditions outside the attacker's control, so it takes preparation. |
| Privileges required | None | No account or privileges are needed. |
| User interaction | None | No action from any user is needed. |
| Scope | Unchanged | The impact stays within the vulnerable component. |
| Confidentiality impact | None | No effect on the secrecy of data. |
| Integrity impact | Low | Limited effect on the trustworthiness of data. |
| Availability impact | None | No effect on availability. |
CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at first.org/cvss.
EPSS
- Score
- 0.99860 (99.9% probability)
- Percentile
- 99.96%
- Scores of
- Nov 10, 2026
- Model
- v2026.06.15
CISA assessment as of May 27, 2026
- Automatable
- no
- Technical impact
- partial
Weakness (CWE)
- CWE-295Improper Certificate Validation
References
- SUSE-SU-2015:1184 (lists.opensuse.org)vendor-advisory
- SUSE-SU-2015:1177 (lists.opensuse.org)vendor-advisory
- SSRT102180 (marc.info)vendor-advisory
- RHSA-2015:1243 (rhn.redhat.com)vendor-advisory
- openSUSE-SU-2015:1229 (lists.opensuse.org)vendor-advisory
- 1033208 (securitytracker.com)vdb-entry
- 1032637 (securitytracker.com)vdb-entry
- HPSBGN03404 (marc.info)vendor-advisory
- DSA-3688 (debian.org)vendor-advisory
- DSA-3287 (debian.org)vendor-advisory
- HPSBUX03512 (marc.info)vendor-advisory
- 1032865 (securitytracker.com)vdb-entry
- HPSBGN03351 (marc.info)vendor-advisory
- SUSE-SU-2015:1268 (lists.opensuse.org)vendor-advisory
- SUSE-SU-2015:1150 (lists.opensuse.org)vendor-advisory
- 1034728 (securitytracker.com)vdb-entry
- SUSE-SU-2015:1183 (lists.opensuse.org)vendor-advisory
- 1032656 (securitytracker.com)vdb-entry
- RHSA-2016:2056 (rhn.redhat.com)vendor-advisory
- [oss-security] 20150520 CVE-2015-4000 - TLS does not properly convey server's ciphersuite choice (openwall.com)mailing-list
- openSUSE-SU-2015:1684 (lists.opensuse.org)vendor-advisory
- HPSBGN03361 (marc.info)vendor-advisory
- HPSBGN03399 (marc.info)vendor-advisory
- 1032475 (securitytracker.com)vdb-entry
- 1032960 (securitytracker.com)vdb-entry
- openSUSE-SU-2016:0255 (lists.opensuse.org)vendor-advisory
- 1032653 (securitytracker.com)vdb-entry
- SUSE-SU-2016:0224 (lists.opensuse.org)vendor-advisory
- 1033385 (securitytracker.com)vdb-entry
- GLSA-201512-10 (security.gentoo.org)vendor-advisory
- RHSA-2015:1229 (rhn.redhat.com)vendor-advisory
- openSUSE-SU-2016:0483 (lists.opensuse.org)vendor-advisory
- 1032864 (securitytracker.com)vdb-entry
- 1032910 (securitytracker.com)vdb-entry
- 1032645 (securitytracker.com)vdb-entry
- USN-2706-1 (ubuntu.com)vendor-advisory
- GLSA-201701-46 (security.gentoo.org)vendor-advisory
- RHSA-2015:1526 (rhn.redhat.com)vendor-advisory
- 1033760 (securitytracker.com)vdb-entry
- RHSA-2015:1485 (rhn.redhat.com)vendor-advisory
- RHSA-2015:1197 (rhn.redhat.com)vendor-advisory
- HPSBMU03401 (marc.info)vendor-advisory
- 1032699 (securitytracker.com)vdb-entry
- 1032476 (securitytracker.com)vdb-entry
- 1032649 (securitytracker.com)vdb-entry
- HPSBMU03345 (marc.info)vendor-advisory
- HPSBUX03363 (marc.info)vendor-advisory
- RHSA-2015:1544 (rhn.redhat.com)vendor-advisory
- FEDORA-2015-9130 (lists.fedoraproject.org)vendor-advisory
- SUSE-SU-2015:1182 (lists.opensuse.org)vendor-advisory
- SSRT102112 (h20564.www2.hp.com)vendor-advisory
- 1032688 (securitytracker.com)vdb-entry
- SUSE-SU-2015:1143 (lists.opensuse.org)vendor-advisory
- 1032652 (securitytracker.com)vdb-entry
- FEDORA-2015-9048 (lists.fedoraproject.org)vendor-advisory
- RHSA-2015:1185 (rhn.redhat.com)vendor-advisory
- HPSBGN03362 (marc.info)vendor-advisory
- APPLE-SA-2015-06-30-2 (lists.apple.com)vendor-advisory
- openSUSE-SU-2015:1289 (lists.opensuse.org)vendor-advisory
- FEDORA-2015-9161 (lists.fedoraproject.org)vendor-advisory
- HPSBGN03402 (marc.info)vendor-advisory
- 1032648 (securitytracker.com)vdb-entry
- 1032759 (securitytracker.com)vdb-entry
- RHSA-2015:1228 (rhn.redhat.com)vendor-advisory
- HPSBGN03405 (marc.info)vendor-advisory
- DSA-3316 (debian.org)vendor-advisory
- 1033209 (securitytracker.com)vdb-entry
- 1032871 (securitytracker.com)vdb-entry
- DSA-3324 (debian.org)vendor-advisory
- 1032655 (securitytracker.com)vdb-entry
- 1033210 (securitytracker.com)vdb-entry
- HPSBGN03411 (marc.info)vendor-advisory
- openSUSE-SU-2015:1277 (lists.opensuse.org)vendor-advisory
- HPSBGN03533 (marc.info)vendor-advisory
- USN-2673-1 (ubuntu.com)vendor-advisory
- 1034884 (securitytracker.com)vdb-entry
- HPSBMU03356 (marc.info)vendor-advisory
- GLSA-201603-11 (security.gentoo.org)vendor-advisory
- 1033064 (securitytracker.com)vdb-entry
- SUSE-SU-2015:1181 (lists.opensuse.org)vendor-advisory
- 1032778 (securitytracker.com)vdb-entry
- 1032474 (securitytracker.com)vdb-entry
- HPSBGN03407 (marc.info)vendor-advisory
- openSUSE-SU-2015:1209 (lists.opensuse.org)vendor-advisory
- 1032784 (securitytracker.com)vdb-entry
- 1032777 (securitytracker.com)vdb-entry
- 1033416 (securitytracker.com)vdb-entry
- 1033991 (securitytracker.com)vdb-entry
- 1032647 (securitytracker.com)vdb-entry
- 1032654 (securitytracker.com)vdb-entry
- 1033341 (securitytracker.com)vdb-entry
- RHSA-2015:1486 (rhn.redhat.com)vendor-advisory
- SUSE-SU-2015:1663 (lists.opensuse.org)vendor-advisory
- 1033433 (securitytracker.com)vdb-entry
- USN-2696-1 (ubuntu.com)vendor-advisory
- APPLE-SA-2015-06-30-1 (lists.apple.com)vendor-advisory
- 1032702 (securitytracker.com)vdb-entry
- DSA-3339 (debian.org)vendor-advisory
- 1032727 (securitytracker.com)vdb-entry
- RHSA-2015:1242 (rhn.redhat.com)vendor-advisory
and 117 more in the record on cve.org
Timeline
- ID reserved
- Record published
- Record last updated
Look up another CVE
About CubePath
Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:47 UTC. Sources and licenses