CVE-2023-49082: Aiohttp Aiohttp's ClientSession Is Vulnerable To Vulnerability

MODERATE
Advisory Identifier: GHSA-qvrw-v9rv-5rjx
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CVSS 5.3
CWE-20
Published
Advisory Summary

CVE-2023-49082 is a MODERATE (CVSS 5.3) aiohttp's clientsession is vulnerable to vulnerability (CWE-20: Improper Input Validation) affecting Aiohttp libraries in the PyPI ecosystem. The issue involves aiohttp's clientsession is vulnerable to crlf injection via method. Remediation is available by upgrading affected packages to version 3.9.0.

CVE-2023-49082 at a Glance

CVE Identifier CVE-2023-49082
GHSA Identifier GHSA-qvrw-v9rv-5rjx
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-20: Improper Input Validation
Affected Product Aiohttp
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 5.3

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:L/A:N).

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 Low (I:L)
Availability None (A:N)

How to Fix CVE-2023-49082

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

aiohttp fixed: 3.9.0 
pip install aiohttp>=3.9.0
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 aiohttp

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2023-49082, inspect your installed packages using pip:

pip show aiohttp

Analyze the terminal output to locate any version of Aiohttp in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.9.0), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-20: Improper Input Validation, where the product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. In Aiohttp, 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

### Summary Improper validation makes it possible for an attacker to modify the HTTP request (e.g. insert a new header) or even create a new HTTP request if the attacker controls the HTTP method. ### Details The vulnerability occurs only if the attacker can control the HTTP method (GET, POST etc.) of the request. Previous releases performed no validation on the provided value. If an attacker controls the HTTP method it will be used as is and can lead to HTTP request smuggling. ### PoC A minimal example can be found here: https://gist.github.com/jnovikov/7f411ae9fe6a9a7804cf162a3bdbb44b ### Impact If the attacker can control the HTTP version of the request it will be able to modify the request (request smuggling). ### Workaround If unable to upgrade and using user-provided values for the request method, perform manual validation of the user value (e.g. by restricting it to a few known values like GET, POST etc.). Patch: https://github.com/aio-libs/aiohttp/pull/7806/files

CVE-2023-49082 Affected Aiohttp Versions

1 component(s)
Fixed Versions:
3.9.0
Product / Package Ecosystem Affected Versions Fixed Version
aiohttp
pypi/aiohttp
PyPI
< 3.9.0
3.9.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-qvrw-v9rv-5rjx
NVD — CVE-2023-49082 NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-49082
Aiohttp Source Repository REPOSITORY
https://github.com/aio-libs/aiohttp/pull/7806/files
Security Fix Commit FIX COMMIT
https://github.com/aio-libs/aiohttp/commit/e4ae01c2077d2cfa116aa82e4ff6866857f7c466
Aiohttp Source Repository REPOSITORY
https://gist.github.com/jnovikov/7f411ae9fe6a9a7804cf162a3bdbb44b
Aiohttp Source Repository REPOSITORY
https://github.com/aio-libs/aiohttp
Aiohttp Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/aiohttp/PYSEC-2023-251.yaml
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2025/02/msg00002.html
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TY5SI6NK5243DEEDQUFKQKW5GQNKQUMA
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WSYWMP64ZFCTC3VO6RY6EC6VSSMV6I3A

Frequently Asked Questions

What is CVE-2023-49082?
CVE-2023-49082 is a security vulnerability in Aiohttp involving aiohttp's ClientSession is vulnerable to CRLF injection via method under CWE-20: Improper Input Validation.
Which Aiohttp versions are affected?
Affected versions include releases prior to 3.9.0 across affected packages: aiohttp.
What version fixes CVE-2023-49082?
Upgrading to 3.9.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is aiohttp affected?
Yes, aiohttp is affected in releases prior to 3.9.0. Upgrade your dependency to 3.9.0 or later.
What is the CVSS score of CVE-2023-49082?
CVE-2023-49082 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.
What CWE is associated with CVE-2023-49082?
CVE-2023-49082 is classified under CWE-20: Improper Input Validation (The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.).
How can I check PyPI dependencies for CVE-2023-49082?
Run the dependency tree command: 'pip show aiohttp'. 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-qvrw-v9rv-5rjx",
  "modified" : "2025-11-03T22:31:47Z",
  "published" : "2023-11-27T23:17:24Z",
  "aliases" : [ "CVE-2023-49082" ],
  "summary" : "aiohttp's ClientSession is vulnerable to CRLF injection via method",
  "details" : "### Summary\nImproper validation makes it possible for an attacker to modify the HTTP request (e.g. insert a new header) or even create a new HTTP request if the attacker controls the HTTP method.\n\n### Details\nThe vulnerability occurs only if the attacker can control the HTTP method (GET, POST etc.) of the request.\n\nPrevious releases performed no validation on the provided value. If an attacker controls the HTTP method it will be used as is and can lead to HTTP request smuggling.\n\n### PoC\nA minimal example can be found here:\nhttps://gist.github.com/jnovikov/7f411ae9fe6a9a7804cf162a3bdbb44b\n\n### Impact\nIf the attacker can control the HTTP version of the request it will be able to modify the request (request smuggling).\n\n### Workaround\nIf unable to upgrade and using user-provided values for the request method, perform manual validation of the user value (e.g. by restricting it to a few known values like GET, POST etc.).\n\nPatch: https://github.com/aio-libs/aiohttp/pull/7806/files",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "aiohttp"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.9.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-qvrw-v9rv-5rjx"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-49082"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/aio-libs/aiohttp/pull/7806/files"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/aio-libs/aiohttp/commit/e4ae01c2077d2cfa116aa82e4ff6866857f7c466"
  }, {
    "type" : "WEB",
    "url" : "https://gist.github.com/jnovikov/7f411ae9fe6a9a7804cf162a3bdbb44b"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/aio-libs/aiohttp"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/aiohttp/PYSEC-2023-251.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2025/02/msg00002.html"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TY5SI6NK5243DEEDQUFKQKW5GQNKQUMA"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WSYWMP64ZFCTC3VO6RY6EC6VSSMV6I3A"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-11-27T23:17:24Z",
    "nvd_published_at" : "2023-11-29T20:15:08Z"
  }
}