Vulnerabilities in pkg:pypi/postfix-mta-sts-resolver
PACKAGECVE-2019-16791 is a HIGH (CVSS 6.9) postfix-mta-sts-resolver algorithm downgrade vulnerability vulnerability (CWE-757: Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')) affecting Postfix mta sts resolver libraries in the PyPI ecosystem. The issue involves postfix-mta-sts-resolver algorithm downgrade vulnerability. Remediation is available by upgrading affected packages to version 0.5.1.
pkg:pypi/postfix-mta-sts-resolver
Vulnerability advisories affecting package pkg:pypi/postfix-mta-sts-resolver. Select an advisory below to view technical details or fixes.
| Advisory ID | CVE / NVD | Severity | Summary |
|---|---|---|---|
| GHSA-h92m-42h4-82f6 | CVE-2019-16791 | HIGH | postfix-mta-sts-resolver Algorithm Downgrade vulnerability |
CVE-2019-16791 at a Glance
Security Impact
CVSS: 6.9
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:N).
How to Fix CVE-2019-16791
To remediate this vulnerability, upgrade all affected Postfix mta sts resolver dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
pip install postfix-mta-sts-resolver>=0.5.1Run the following command in your project directory to verify that all resolved dependencies use the patched release:
pip show postfix-mta-sts-resolverHow to Check if You Are Affected
To determine whether your Python environment is affected by CVE-2019-16791, inspect your installed packages using pip:
pip show postfix-mta-sts-resolverAnalyze the terminal output to locate any version of Postfix mta sts resolver in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.5.1), your application is affected.
Note: The pip show postfix-mta-sts-resolver command checks currently installed packages in your active Python environment.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-757: Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade'), where a protocol or its implementation supports interaction between multiple actors and allows those actors to negotiate which algorithm should be used as a protection mechanism such as encryption or authentication, but it does not select the strongest algorithm that is available to both parties. In Postfix mta sts resolver, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2019-16791 Affected Postfix mta sts resolver Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
postfix-mta-sts-resolver
|
PyPI |
< 0.5.1
|
0.5.1
|
References
Frequently Asked Questions
What is CVE-2019-16791?
Which Postfix mta sts resolver versions are affected?
What version fixes CVE-2019-16791?
Is postfix-mta-sts-resolver affected?
What is the CVSS score of CVE-2019-16791?
What CWE is associated with CVE-2019-16791?
How can I check PyPI dependencies for CVE-2019-16791?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-h92m-42h4-82f6",
"modified" : "2024-10-21T20:07:58Z",
"published" : "2019-07-05T21:06:58Z",
"aliases" : [ "CVE-2019-16791" ],
"summary" : "postfix-mta-sts-resolver Algorithm Downgrade vulnerability",
"details" : "## Incorrect query parsing\n\n### Impact\nAll users of versions prior to 0.5.1 can receive incorrect response from daemon under rare conditions, rendering downgrade of effective STS policy.\n\n### Patches\nProblem has been patched in version 0.5.1\n\n### Workarounds\nUsers may remediate this vulnerability without upgrading by applying [these patches](https://gist.github.com/Snawoot/b9da85d6b26dea5460673b29df1adc6b) to older suppoorted versions.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [postfix-mta-sts-resolver repo](https://github.com/Snawoot/postfix-mta-sts-resolver)\n* Email me at [vladislav at vm-0 dot com](mailto:vladislav-ex-gh-advisory@vm-0.com)",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:N"
}, {
"type" : "CVSS_V4",
"score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "PyPI",
"name" : "postfix-mta-sts-resolver"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "0.5.1"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/Snawoot/postfix-mta-sts-resolver/security/advisories/GHSA-h92m-42h4-82f6"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-16791"
}, {
"type" : "WEB",
"url" : "https://gist.github.com/Snawoot/b9da85d6b26dea5460673b29df1adc6b"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/Snawoot/postfix-mta-sts-resolver"
}, {
"type" : "WEB",
"url" : "https://github.com/pypa/advisory-database/tree/main/vulns/postfix-mta-sts-resolver/PYSEC-2020-174.yaml"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-757" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2020-06-16T21:39:43Z",
"nvd_published_at" : null
}
}