CVE-2020-28473: Bottle Bottle HTTP Request Smuggling Vulnerability

MODERATE
Advisory Identifier: GHSA-qhx9-7hx7-cp4r
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CVSS 6.8
CWE-444
Published
Advisory Summary

CVE-2020-28473 is a MODERATE (CVSS 6.8) bottle http request smuggling vulnerability (CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')) affecting Bottle libraries in the PyPI ecosystem. The issue involves bottle http request smuggling. Remediation is available by upgrading affected packages to version 0.12.19.

CVE-2020-28473 at a Glance

CVE Identifier CVE-2020-28473
GHSA Identifier GHSA-qhx9-7hx7-cp4r
Severity MODERATE
CVSS v3.1 Base Score 6.8
CWE Classification CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Affected Product Bottle
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 6.8

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

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

How to Fix CVE-2020-28473

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

bottle fixed: 0.12.19 
pip install bottle>=0.12.19
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 bottle

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2020-28473, inspect your installed packages using pip:

pip show bottle

Analyze the terminal output to locate any version of Bottle in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.12.19), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling'), where the product acts as an intermediary http agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed http requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. In Bottle, 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 package bottle before 0.12.19 are vulnerable to Web Cache Poisoning by using a vector called parameter cloaking. When the attacker can separate query parameters using a semicolon (;), they can cause a difference in the interpretation of the request between the proxy (running with default configuration) and the server. This can result in malicious requests being cached as completely safe ones, as the proxy would usually not see the semicolon as a separator, and therefore would not include it in a cache key of an unkeyed parameter.

CVE-2020-28473 Affected Bottle Versions

1 component(s)
Fixed Versions:
0.12.19
Product / Package Ecosystem Affected Versions Fixed Version
bottle
pypi/bottle
PyPI
< 0.12.19
0.12.19

References

NVD — CVE-2020-28473 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-28473
Security Fix Commit FIX COMMIT
https://github.com/bottlepy/bottle/commit/57a2f22e0c1d2b328c4f54bf75741d74f47f1a6b
GitHub Advisory / Wiki ADVISORY
https://github.com/advisories/GHSA-qhx9-7hx7-cp4r
Bottle Source Repository REPOSITORY
https://github.com/bottlepy/bottle
Bottle Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/bottle/PYSEC-2021-129.yaml
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2021/01/msg00019.html
snyk.io/blog/cache-poisonin... WEB
https://snyk.io/blog/cache-poisoning-in-popular-open-source-packages
snyk.io/vuln/snyk-python-bo... WEB
https://snyk.io/vuln/SNYK-PYTHON-BOTTLE-1017108

Frequently Asked Questions

What is CVE-2020-28473?
CVE-2020-28473 is a security vulnerability in Bottle involving bottle HTTP Request smuggling under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling').
Which Bottle versions are affected?
Affected versions include releases prior to 0.12.19 across affected packages: bottle.
What version fixes CVE-2020-28473?
Upgrading to 0.12.19 (or the latest patched release for your respective branch) resolves the vulnerability.
Is bottle affected?
Yes, bottle is affected in releases prior to 0.12.19. Upgrade your dependency to 0.12.19 or later.
What is the CVSS score of CVE-2020-28473?
CVE-2020-28473 has a CVSS v3.1 base score of 6.8 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H.
What CWE is associated with CVE-2020-28473?
CVE-2020-28473 is classified under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') (The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.).
How can I check PyPI dependencies for CVE-2020-28473?
Run the dependency tree command: 'pip show bottle'. 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-qhx9-7hx7-cp4r",
  "modified" : "2024-09-13T14:20:37Z",
  "published" : "2021-04-07T21:05:21Z",
  "aliases" : [ "CVE-2020-28473" ],
  "summary" : "bottle HTTP Request smuggling",
  "details" : "The package bottle before 0.12.19 are vulnerable to Web Cache Poisoning by using a vector called parameter cloaking. When the attacker can separate query parameters using a semicolon (;), they can cause a difference in the interpretation of the request between the proxy (running with default configuration) and the server. This can result in malicious requests being cached as completely safe ones, as the proxy would usually not see the semicolon as a separator, and therefore would not include it in a cache key of an unkeyed parameter.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "bottle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.12.19"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-28473"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/bottlepy/bottle/commit/57a2f22e0c1d2b328c4f54bf75741d74f47f1a6b"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-qhx9-7hx7-cp4r"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/bottlepy/bottle"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/bottle/PYSEC-2021-129.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2021/01/msg00019.html"
  }, {
    "type" : "WEB",
    "url" : "https://snyk.io/blog/cache-poisoning-in-popular-open-source-packages"
  }, {
    "type" : "WEB",
    "url" : "https://snyk.io/vuln/SNYK-PYTHON-BOTTLE-1017108"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-444" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-04-06T20:59:20Z",
    "nvd_published_at" : "2021-01-18T12:15:00Z"
  }
}