CVE-2019-16226: Lmdb LMDB Invalid Write Vulnerability

HIGH
Advisory Identifier: GHSA-r8g9-w4f3-9crm
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CVSS 7.5
CWE-787
Published
Advisory Summary

CVE-2019-16226 is a HIGH (CVSS 7.5) lmdb invalid write vulnerability (CWE-787: Out-of-bounds Write) affecting Lmdb libraries in the PyPI ecosystem. The issue involves lmdb invalid write. Remediation is available in the latest vendor maintenance releases.

CVE-2019-16226 at a Glance

CVE Identifier CVE-2019-16226
GHSA Identifier GHSA-r8g9-w4f3-9crm
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-787: Out-of-bounds Write
Affected Product Lmdb
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2019-16226

To remediate this vulnerability, upgrade all affected Lmdb dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

lmdb fixed: Latest secure release 
pip install lmdb>=Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show lmdb

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2019-16226, inspect your installed packages using pip:

pip show lmdb

Analyze the terminal output to locate any version of Lmdb in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The pip show lmdb command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-787: Out-of-bounds Write, where the product writes data past the end, or before the beginning, of the intended buffer. In Lmdb, 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

An issue was discovered in py-lmdb 0.97. `mdb_node_del` does not validate a `memmove` in the case of an unexpected `node->mn_hi`, leading to an invalid write operation.

CVE-2019-16226 Affected Lmdb Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
lmdb
pypi/lmdb
PyPI
≤ 0.97

References

NVD — CVE-2019-16226 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-16226
Lmdb Source Repository REPOSITORY
https://github.com/jnwatson/py-lmdb/issues/210
Lmdb Source Repository REPOSITORY
https://github.com/LMDB/lmdb/blob/mdb.master/libraries/liblmdb/mdb.c#L8443-L8498
Lmdb Source Repository REPOSITORY
https://github.com/TeamSeri0us/pocs/tree/master/lmdb/lmdb%20memory%20corruption%20vuln
Lmdb Source Repository REPOSITORY
https://github.com/jnwatson/py-lmdb
Lmdb Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/lmdb/PYSEC-2019-238.yaml
pypi.org/project/lmdb WEB
https://pypi.org/project/lmdb

Frequently Asked Questions

What is CVE-2019-16226?
CVE-2019-16226 is a security vulnerability in Lmdb involving LMDB invalid write under CWE-787: Out-of-bounds Write.
Which Lmdb versions are affected?
Affected versions include releases prior to current release patches across affected packages: lmdb.
What version fixes CVE-2019-16226?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is lmdb affected?
Yes, lmdb is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2019-16226?
CVE-2019-16226 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2019-16226?
CVE-2019-16226 is classified under CWE-787: Out-of-bounds Write (The product writes data past the end, or before the beginning, of the intended buffer.).
How can I check PyPI dependencies for CVE-2019-16226?
Run the dependency tree command: 'pip show lmdb'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-r8g9-w4f3-9crm",
  "modified" : "2024-09-30T16:46:56Z",
  "published" : "2022-05-24T16:55:55Z",
  "aliases" : [ "CVE-2019-16226" ],
  "summary" : "LMDB invalid write ",
  "details" : "An issue was discovered in py-lmdb 0.97. `mdb_node_del` does not validate a `memmove` in the case of an unexpected `node->mn_hi`, leading to an invalid write operation.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "lmdb"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.97"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-16226"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jnwatson/py-lmdb/issues/210"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/LMDB/lmdb/blob/mdb.master/libraries/liblmdb/mdb.c#L8443-L8498"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/TeamSeri0us/pocs/tree/master/lmdb/lmdb%20memory%20corruption%20vuln"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/jnwatson/py-lmdb"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/lmdb/PYSEC-2019-238.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://pypi.org/project/lmdb"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-787" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-07-17T22:49:02Z",
    "nvd_published_at" : "2019-09-11T15:15:00Z"
  }
}