libssh: Authentication Bypass due to improper message callbacks implementation
Published Oct 17, 2018
9.1
CRITICALCVSS 3.0
EPSS 91.79%
Description
A vulnerability was found in libssh's server-side state machine before versions 0.7.6 and 0.8.4. A malicious client could create channels without first performing authentication, resulting in unauthorized access.
Affected products
- Vendor n/a Product Libssh Defaultn/a
- Version 0.7.6StatusaffectedConstraints-
- Version 0.8.4StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n/a | Libssh | n/a |
|
Configuration 1
Configuration 2
- 14.04
- 16.04
- 18.04
- 18.10
Configuration 3
- 8.0
- 9.0
Configuration 4
- 7.0
Configuration 5
- ≥ 7.3
- ≥ 9.4
- n/a
- n/a
- n/a
Configuration 6
- ≤ 8.0.13
No data.
Red Hat Enterprise Linux 7 Extras
cockpit-0:176-4.el7
Fixed · RHBA-2018:3712
Red Hat Enterprise Linux 7 Extras
libssh-0:0.7.1-7.el7
Fixed · RHBA-2018:3712
Red Hat Enterprise Linux 6
libssh2
Not affected
Red Hat Enterprise Linux 7
libssh2
Not affected
Red Hat Enterprise Linux 8
libssh
Not affected
Red Hat Enterprise Linux 8
libssh2
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 7 Extras | cockpit-0:176-4.el7 | Fixed | RHBA-2018:3712 |
| Red Hat Enterprise Linux 7 Extras | libssh-0:0.7.1-7.el7 | Fixed | RHBA-2018:3712 |
| Red Hat Enterprise Linux 6 | libssh2 | Not affected | n/a |
| Red Hat Enterprise Linux 7 | libssh2 | Not affected | n/a |
| Red Hat Enterprise Linux 8 | libssh | Not affected | n/a |
| Red Hat Enterprise Linux 8 | libssh2 | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This vulnerability affects libssh shipped in Red Hat Enterprise Linux 7 Extras. No libssh packages are included in Red Hat Enterprise Linux 6 and earlier. This issue does not affect libssh2 or openssh. This issue can only be affect applications that use libssh to implement an SSH server; SSH client functionality is not affected. No packages in Red Hat products use libssh to implement an SSH server. Therefore, no package from Red Hat that uses the libssh library is affected by this flaw. The libssh library is available for customer or third party code to use. Such code that is linked against libssh and uses the `ssh_bind*` functions may be affected by this flaw.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
AV:N/AC:L/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 2, 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 (62 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 91.79% (0.91789) | 99.81th | v5 (v2026.06.15) |
| Jun 15, 2026 | 91.79% (0.91789) | 99.80th | v5 (v2026.06.15) |
| Jun 10, 2026 | 74.91% (0.74906) | 98.89th | v4 (v2025.03.14) |
| Mar 4, 2026 | 78.33% (0.78329) | 99.00th | v4 (v2025.03.14) |
| Mar 1, 2026 | 79.73% (0.79731) | 99.07th | v4 (v2025.03.14) |
| Feb 4, 2026 | 78.33% (0.78329) | 98.99th | v4 (v2025.03.14) |
| Feb 1, 2026 | 79.73% (0.79731) | 99.06th | v4 (v2025.03.14) |
| Jan 4, 2026 | 78.33% (0.78329) | 98.98th | v4 (v2025.03.14) |
| Jan 1, 2026 | 79.73% (0.79731) | 99.06th | v4 (v2025.03.14) |
| Dec 28, 2025 | 78.33% (0.78329) | 98.98th | v4 (v2025.03.14) |
| Dec 27, 2025 | 75.93% (0.75930) | 98.87th | v4 (v2025.03.14) |
| Dec 4, 2025 | 78.33% (0.78329) | 98.97th | v4 (v2025.03.14) |
| Dec 1, 2025 | 79.73% (0.79731) | 99.05th | v4 (v2025.03.14) |
| Nov 21, 2025 | 78.33% (0.78329) | 98.97th | v4 (v2025.03.14) |
| Nov 18, 2025 | 17.76% (0.17757) | 94.62th | v4 (v2025.03.14) |
| Nov 4, 2025 | 78.33% (0.78329) | 98.98th | v4 (v2025.03.14) |
| Nov 1, 2025 | 79.73% (0.79731) | 99.05th | v4 (v2025.03.14) |
| Oct 28, 2025 | 78.33% (0.78329) | 98.98th | v4 (v2025.03.14) |
| Oct 27, 2025 | 75.93% (0.75930) | 98.86th | v4 (v2025.03.14) |
| Oct 4, 2025 | 78.33% (0.78329) | 98.98th | v4 (v2025.03.14) |
| Oct 1, 2025 | 79.73% (0.79731) | 99.06th | v4 (v2025.03.14) |
| Sep 5, 2025 | 75.93% (0.75930) | 98.87th | v4 (v2025.03.14) |
| Sep 1, 2025 | 77.52% (0.77515) | 98.95th | v4 (v2025.03.14) |
| Aug 16, 2025 | 75.93% (0.75930) | 98.87th | v4 (v2025.03.14) |
| Aug 4, 2025 | 79.38% (0.79379) | 99.03th | v4 (v2025.03.14) |
| Aug 1, 2025 | 80.88% (0.80880) | 99.11th | v4 (v2025.03.14) |
| Jul 5, 2025 | 79.58% (0.79577) | 99.02th | v4 (v2025.03.14) |
| Jul 1, 2025 | 80.88% (0.80880) | 99.10th | v4 (v2025.03.14) |
| Jun 4, 2025 | 79.58% (0.79577) | 99.02th | v4 (v2025.03.14) |
| Jun 1, 2025 | 80.88% (0.80880) | 99.10th | v4 (v2025.03.14) |
| May 14, 2025 | 79.58% (0.79577) | 99.02th | v4 (v2025.03.14) |
| May 13, 2025 | 80.88% (0.80880) | 99.08th | v4 (v2025.03.14) |
| May 4, 2025 | 79.58% (0.79577) | 99.01th | v4 (v2025.03.14) |
| May 1, 2025 | 80.88% (0.80880) | 99.08th | v4 (v2025.03.14) |
| Apr 11, 2025 | 79.58% (0.79577) | 99.04th | v4 (v2025.03.14) |
| Apr 10, 2025 | 80.88% (0.80880) | 99.11th | v4 (v2025.03.14) |
| Mar 24, 2025 | 79.58% (0.79577) | 99.06th | v4 (v2025.03.14) |
| Mar 20, 2025 | 76.53% (0.76526) | 98.91th | v4 (v2025.03.14) |
| Mar 17, 2025 | 79.86% (0.79855) | 99.05th | v4 (v2025.03.14) |
| Jan 20, 2025 | 22.17% (0.22171) | 96.53th | v3 (v2023.03.01) |
| Dec 17, 2024 | 25.95% (0.25948) | 96.72th | v3 (v2023.03.01) |
| Dec 12, 2024 | 13.61% (0.13609) | 95.83th | v3 (v2023.03.01) |
| Jun 5, 2024 | 13.71% (0.13710) | 95.53th | v3 (v2023.03.01) |
| Apr 18, 2024 | 14.23% (0.14233) | 95.62th | v3 (v2023.03.01) |
| Mar 9, 2024 | 15.31% (0.15306) | 95.69th | v3 (v2023.03.01) |
| Jan 26, 2024 | 15.43% (0.15428) | 95.40th | v3 (v2023.03.01) |
| Dec 22, 2023 | 12.49% (0.12494) | 94.91th | v3 (v2023.03.01) |
| Dec 4, 2023 | 11.71% (0.11711) | 94.74th | v3 (v2023.03.01) |
| Nov 15, 2023 | 11.16% (0.11164) | 94.61th | v3 (v2023.03.01) |
| Oct 29, 2023 | 10.52% (0.10518) | 94.38th | v3 (v2023.03.01) |
| Oct 11, 2023 | 9.05% (0.09047) | 93.92th | v3 (v2023.03.01) |
| Sep 26, 2023 | 7.94% (0.07938) | 93.48th | v3 (v2023.03.01) |
| Sep 8, 2023 | 6.82% (0.06824) | 93.04th | v3 (v2023.03.01) |
| Jul 8, 2023 | 7.56% (0.07556) | 93.22th | v3 (v2023.03.01) |
| Jun 14, 2023 | 7.24% (0.07236) | 93.08th | v3 (v2023.03.01) |
| Jun 2, 2023 | 6.35% (0.06345) | 92.57th | v3 (v2023.03.01) |
| Mar 7, 2023 | 5.29% (0.05290) | 91.83th | v3 (v2023.03.01) |
| Mar 6, 2023 | 92.17% (0.92171) | 99.90th | v2 (v2022.01.01) |
| Feb 4, 2022 | 92.17% (0.92171) | 99.89th | v2 (v2022.01.01) |
| Feb 3, 2022 | 45.70% (0.45700) | 98.88th | v1 |
| Sep 1, 2021 | 45.70% (0.45700) | 99.50th | v1 |
| Apr 14, 2021 | 45.70% (0.45700) | 0.00th | v1 |
References (15)
- http://www.securityfocus.com/bid/105677 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- https://access.redhat.com/security/cve/CVE-2018-10933 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1614973 Issue Tracking
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-10933 x_refsource_CONFIRMIssue TrackingThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2018/10/msg00010.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2018-10933
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2018-0016 x_refsource_CONFIRMThird Party Advisory
- https://security.netapp.com/advisory/ntap-20190118-0002/ x_refsource_CONFIRMThird Party Advisory
- https://usn.ubuntu.com/3795-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://usn.ubuntu.com/3795-2/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2018-10933
- https://www.debian.org/security/2018/dsa-4322 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- https://www.exploit-db.com/exploits/45638/ exploitx_refsource_EXPLOIT-DBThird Party AdvisoryVDB Entry
- https://www.libssh.org/security/advisories/CVE-2018-10933.txt x_refsource_CONFIRMVendor Advisory
- https://www.oracle.com/technetwork/security-advisory/cpujan2019-5072801.html x_refsource_CONFIRMPatchThird Party Advisory
Change history (0)
No recorded changes yet.