The int_x509_param_set_hosts function in lib/libcrypto/x509/x509_vpm.c in LibreSSL 2.7.0 before 2.7.1 does not support a certain special case of a zero name length, which causes silent omission of hostname verification, and consequently allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate
Published Mar 24, 2018
7.4
HIGHCVSS 3.0
EPSS 1.02%
Description
The int_x509_param_set_hosts function in lib/libcrypto/x509/x509_vpm.c in LibreSSL 2.7.0 before 2.7.1 does not support a certain special case of a zero name length, which causes silent omission of hostname verification, and consequently allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate. NOTE: the LibreSSL documentation indicates that this special case is supported, but the BoringSSL documentation does not.
Affected products
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
AV:N/AC:M/Au:N/C:P/I:P/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (21 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 1.02% (0.01020) | 62.08th | v5 (v2026.06.15) |
| Jun 15, 2026 | 1.06% (0.01056) | 59.88th | v5 (v2026.06.15) |
| Mar 30, 2025 | 0.40% (0.00397) | 57.64th | v4 (v2025.03.14) |
| Mar 29, 2025 | 3.14% (0.03139) | 78.02th | v4 (v2025.03.14) |
| Mar 28, 2025 | 0.40% (0.00397) | 57.69th | v4 (v2025.03.14) |
| Mar 27, 2025 | 3.14% (0.03139) | 85.24th | v4 (v2025.03.14) |
| Mar 20, 2025 | 0.40% (0.00397) | 57.90th | v4 (v2025.03.14) |
| Mar 19, 2025 | 4.01% (0.04014) | 87.08th | v4 (v2025.03.14) |
| Mar 17, 2025 | 0.40% (0.00397) | 58.46th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.08% (0.00077) | 35.12th | v3 (v2023.03.01) |
| Aug 15, 2023 | 0.08% (0.00077) | 31.91th | v3 (v2023.03.01) |
| Jul 8, 2023 | 0.07% (0.00068) | 27.94th | v3 (v2023.03.01) |
| Mar 18, 2023 | 0.09% (0.00088) | 36.16th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.10% (0.00104) | 41.05th | v3 (v2023.03.01) |
| Mar 6, 2023 | 12.49% (0.12492) | 95.36th | v2 (v2022.01.01) |
| Apr 1, 2022 | 12.49% (0.12492) | 95.00th | v2 (v2022.01.01) |
| Feb 4, 2022 | 12.49% (0.12492) | 89.83th | v2 (v2022.01.01) |
| Feb 3, 2022 | 3.63% (0.03630) | 71.73th | v1 |
| Jan 6, 2022 | 3.63% (0.03630) | 71.48th | v1 |
| Sep 1, 2021 | 3.63% (0.03630) | 82.60th | v1 |
| Apr 14, 2021 | 3.63% (0.03630) | 0.00th | v1 |
References (3)
- https://boringssl.googlesource.com/boringssl/+/e759a9cd84198613199259dbed401f4951747cff x_refsource_MISCThird Party Advisory
- https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-2.7.1-relnotes.txt x_refsource_MISCVendor Advisory
- https://github.com/libressl-portable/openbsd/commit/0654414afcce51a16d35d05060190a3ec4618d42 x_refsource_MISCPatchThird Party Advisory
| Link | Providers | Tags |
|---|---|---|
| https://boringssl.googlesource.com/boringssl/+/e759a9cd84198613199259dbed401f4951747cff | x_refsource_MISCThird Party Advisory | |
| https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-2.7.1-relnotes.txt | x_refsource_MISCVendor Advisory | |
| https://github.com/libressl-portable/openbsd/commit/0654414afcce51a16d35d05060190a3ec4618d42 | x_refsource_MISCPatchThird Party Advisory |
Change history (0)
No recorded changes yet.