CVE-2018-1000807

Python Cryptographic Authority pyopenssl version prior to version 17.5.0 contains a CWE-416: Use After Free vulnerability in X509 object handling that can result in Use after free can lead to possible denial of service or remote code execution.. This attack appear to be exploitable via Depends on the calling application and if it retains a reference to the memory.. This vulnerability appears to have been fixed in 17.5.0.

Published: 2018-10-08 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2018-1000807 is rated Moderate Risk (62.5/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.88%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2018-1000807

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-24 3.03% 2.88% -0.15%
2 2025-12-05 5.33% 3.03% -2.30%
3 2025-12-02 5.33%

Full EPSS history (21 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-1000807

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.2 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
8.6 6.4 [email protected]

Weakness enumeration for CVE-2018-1000807

GitHub Security Advisory for CVE-2018-1000807

GHSA-p28m-34f6-967q · Severity: high · Ecosystem: pip — PyOpenSSL Use-After-Free vulnerability

OS Trackers for CVE-2018-1000807

vendor priority summary link
debian not yet assigned CVE-2018-1000807 not yet assigned priority: Debian including 1 source packages (pyopenssl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-1000807
redhat medium https://access.redhat.com/security/cve/CVE-2018-1000807
suse high CVE-2018-1000807 severity important: SUSE including 461 source package names (amazon/suse-sles-15-sp1-chost-byos-v20210304-hvm-ssd-x86_64, amazon/suse-sles-15-sp1-chost-byos-v20220127-hvm-ssd-x86_64, …), 981 product×package rows across 86 product lines (HPE Helion OpenStack 8, Image SLES12-SP5-Azure-BYOS, … (86 product lines)): Fixed 687, Known Affected 231, Known Not Affected 63. https://www.suse.com/security/cve/CVE-2018-1000807/
ubuntu medium CVE-2018-1000807 medium priority: Ubuntu including 1 source packages (pyopenssl), 5 status rows across 5 suites (bionic, cosmic, trusty, upstream, xenial): not-affected 3, released 2. https://ubuntu.com/security/CVE-2018-1000807

Affected software / configurations for CVE-2018-1000807

Vendor Product Version Raw CPE
pyopenssl pyopenssl < 17.5.0 cpe:2.3:a:pyopenssl:pyopenssl:*:*:*:*:*:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
redhat openstack 13 cpe:2.3:a:redhat:openstack:13:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 7.0 cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_server 7.0 cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 7.0 cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*

References for CVE-2018-1000807

cvelogic Threat Intelligence