CVE-2015-3220: Tlslite Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-4749-p7rx-8jjj
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CVSS 7.5
CWE-119
Published
Advisory Summary

CVE-2015-3220 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer) affecting Tlslite libraries in the PyPI ecosystem. The issue involves tlslite remote denial of service vulnerability. Remediation is available by upgrading affected packages to version 0.4.9.

CVE-2015-3220 at a Glance

CVE Identifier CVE-2015-3220
GHSA Identifier GHSA-4749-p7rx-8jjj
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer
Affected Product Tlslite
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:3.0/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-2015-3220

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

tlslite fixed: 0.4.9 
pip install tlslite>=0.4.9
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 tlslite

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2015-3220, inspect your installed packages using pip:

pip show tlslite

Analyze the terminal output to locate any version of Tlslite in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.4.9), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer, where the product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. this may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data. In Tlslite, 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

The tlslite library before 0.4.9 for Python allows remote attackers to trigger a denial of service (runtime exception and process crash).

CVE-2015-3220 Affected Tlslite Versions

1 component(s)
Fixed Versions:
0.4.9
Product / Package Ecosystem Affected Versions Fixed Version
tlslite
pypi/tlslite
PyPI
< 0.4.9
0.4.9

References

NVD — CVE-2015-3220 NVD
https://nvd.nist.gov/vuln/detail/CVE-2015-3220
Security Fix Commit FIX COMMIT
https://github.com/trevp/tlslite/commit/aca8d4f898b436ff6754e1a9ab96cae976c8a853
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=1254215
Tlslite Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/tlslite/PYSEC-2017-96.yaml
Tlslite Source Repository REPOSITORY
https://github.com/trevp/tlslite
groups.google.com/forum/ WEB
https://groups.google.com/forum/#!topic/tlslite-dev/MoWE7B0A4iU

Frequently Asked Questions

What is CVE-2015-3220?
CVE-2015-3220 is a security vulnerability in Tlslite involving tlslite remote denial of service vulnerability under CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer.
Which Tlslite versions are affected?
Affected versions include releases prior to 0.4.9 across affected packages: tlslite.
What version fixes CVE-2015-3220?
Upgrading to 0.4.9 (or the latest patched release for your respective branch) resolves the vulnerability.
Is tlslite affected?
Yes, tlslite is affected in releases prior to 0.4.9. Upgrade your dependency to 0.4.9 or later.
What is the CVSS score of CVE-2015-3220?
CVE-2015-3220 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2015-3220?
CVE-2015-3220 is classified under CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer (The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.).
How can I check PyPI dependencies for CVE-2015-3220?
Run the dependency tree command: 'pip show tlslite'. 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-4749-p7rx-8jjj",
  "modified" : "2024-11-18T21:36:07Z",
  "published" : "2022-05-14T03:07:28Z",
  "aliases" : [ "CVE-2015-3220" ],
  "summary" : "tlslite remote denial of service vulnerability",
  "details" : "The tlslite library before 0.4.9 for Python allows remote attackers to trigger a denial of service (runtime exception and process crash).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/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" : "tlslite"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.4.9"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2015-3220"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/trevp/tlslite/commit/aca8d4f898b436ff6754e1a9ab96cae976c8a853"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=1254215"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/tlslite/PYSEC-2017-96.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/trevp/tlslite"
  }, {
    "type" : "WEB",
    "url" : "https://groups.google.com/forum/#!topic/tlslite-dev/MoWE7B0A4iU"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-119" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-08-02T20:59:14Z",
    "nvd_published_at" : "2017-06-13T16:29:00Z"
  }
}