← Vulnerability feed

Vulnerability record · CVE-2018-1000030 · published 8 February 2018

CVE-2018-1000030: Python use after free vulnerability

Python · Python

Python 2.7.14 is vulnerable to a Heap-Buffer-Overflow as well as a Heap-Use-After-Free. Python versions prior to 2.7.14 may also be vulnerable and it appears that Python 2.7.17 and prior may also be vulnerable however this has not been confirmed. The vulnerability lies when multiply threads are handling large amounts of data. In both cases there is essentially a race condition that occurs. For the Heap-Buffer-Overflow, Thread 2 is creating the size for a buffer, but Thread1 is already writing to the buffer without knowing how much to write. So when a large amount of data is being processed, it is very easy to cause memory corruption using a Heap-Buffer-Overflow. As for the Use-After-Free, Thread3->Malloc->Thread1->Free's->Thread2-Re-uses-Free'd Memory. The PSRT has stated that this is not a security vulnerability due to the fact that the attacker must be able to run code, however in some situations, such as function as a service, this vulnerability can potentially be used by an attacker to violate a trust boundary, as such the DWF feels this issue deserves a CVE.

3.6 CVSS 3.1 Low EPSS 1.2% · top 31.6% CWE-416 · Use after freeCWE-787 · Out-of-bounds write
3.6CVSS 3.1 base score, v2 3.3
1.2%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
14References
8 Oct 2026Last modified by NVD

Description

Python 2.7.14 is vulnerable to a Heap-Buffer-Overflow as well as a Heap-Use-After-Free. Python versions prior to 2.7.14 may also be vulnerable and it appears that Python 2.7.17 and prior may also be vulnerable however this has not been confirmed. The vulnerability lies when multiply threads are handling large amounts of data. In both cases there is essentially a race condition that occurs. For the Heap-Buffer-Overflow, Thread 2 is creating the size for a buffer, but Thread1 is already writing to the buffer without knowing how much to write. So when a large amount of data is being processed, it is very easy to cause memory corruption using a Heap-Buffer-Overflow. As for the Use-After-Free, Thread3->Malloc->Thread1->Free's->Thread2-Re-uses-Free'd Memory. The PSRT has stated that this is not a security vulnerability due to the fact that the attacker must be able to run code, however in some situations, such as function as a service, this vulnerability can potentially be used by an attacker to violate a trust boundary, as such the DWF feels this issue deserves a CVE.

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:L

Affected products

2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://bugs.python.org/issue31530 Issue TrackingPatchVendor Advisory
https://drive.google.com/file/d/1oyR9DAZjZK_SCn3mor6NRAYLJS6ueXaY/view Third Party Advisory
https://security.gentoo.org/glsa/201811-02 Third Party Advisory
https://usn.ubuntu.com/3817-1/ Third Party Advisory
https://usn.ubuntu.com/3817-2/ Third Party Advisory
https://www.dropbox.com/sh/sj3ee7xv55j36k7/AADwP-YfOYikBMuy32e0uvPFa?dl=0 Permissions Required
https://www.oracle.com/security-alerts/cpujan2020.html Third Party Advisory
https://bugs.python.org/issue31530 Issue TrackingPatchVendor Advisory
https://drive.google.com/file/d/1oyR9DAZjZK_SCn3mor6NRAYLJS6ueXaY/view Third Party Advisory
https://security.gentoo.org/glsa/201811-02 Third Party Advisory
https://usn.ubuntu.com/3817-1/ Third Party Advisory
https://usn.ubuntu.com/3817-2/ Third Party Advisory
https://www.dropbox.com/sh/sj3ee7xv55j36k7/AADwP-YfOYikBMuy32e0uvPFa?dl=0 Permissions Required
https://www.oracle.com/security-alerts/cpujan2020.html Third Party Advisory

Track CVE-2018-1000030 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2020-11651SaltStack Salt master authentication bypass in ClearFuncsSaltStack Salt before 2019.2.4 and 3000 before 3000.2 fails to properly validate method calls in the salt-master ClearFuncs class, allowing remote un…KEVEPSS 97%analysed9.8CVE-2020-7247OpenSMTPD MAIL FROM command injection allows remote root code executionOpenSMTPD 6.6, as shipped in OpenBSD 6.6 and other products, mishandles input validation in smtp_mailaddr in smtp_session.c, returning an incorrect v…KEVEPSS 99%analysed9.8CVE-2019-11043PHP-FPM buffer overflow enables remote code executionPHP-FPM in certain configurations writes past allocated buffers into FCGI protocol data space, an out-of-bounds write (CWE-787, CWE-120). It affects …KEVEPSS 100%analysed9.8CVE-2019-16928Exim heap buffer overflow in string_vformat via long EHLO commandExim 4.92 through 4.92.2 contains a heap-based buffer overflow in string_vformat in string.c triggered by a long EHLO command, allowing remote code e…KEVEPSS 42%analysed9.8CVE-2019-10149Exim MTA improper recipient validation leads to remote command executionExim versions 4.87 through 4.91 fail to properly validate recipient addresses in the deliver_message() function in /src/deliver.c, allowing command i…KEVEPSS 100%analysed9.8CVE-2018-6789Exim SMTP base64d buffer overflow allows remote code executionExim before 4.90.1 contains a buffer overflow in the base64d function of its SMTP listener. A handcrafted message can trigger the overflow, and the f…KEVEPSS 82%analysed9.8CVE-2016-8735Apache Tomcat JmxRemoteLifecycleListener remote code executionApache Tomcat's JmxRemoteLifecycleListener was not updated to match the Oracle CVE-2016-3427 credential-type fix, leaving a deserialization weakness …KEVEPSS 90%analysed9.8CVE-2016-3427Oracle Java SE JMX Improper Access Control VulnerabilityCVE-2016-3427 is an unspecified vulnerability in Oracle Java SE 6u113, 7u99, 8u77, Java SE Embedded 8u77, and JRockit R28.3.9, reached through vector…KEVEPSS 92%analysed

Source: NIST National Vulnerability Database (record CVE-2018-1000030), CISA KEV, FIRST EPSS (scores of 2026-11-14). This page is refreshed as NVD updates the record.