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GHSA-27mf-ghqm-j3j8 CVE-2024-52303 PYSEC-2026-1096

aiohttp has a memory leak when middleware is enabled when requesting a resource with a non-allowed method

High PyPI
Severity
0.0 / 10
High · CVSS 4.0
Exploit chance (EPSS)
0.59%
Chance of exploitation in the next 30 days. Higher than 48.29% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-772 Missing Release of Resource after Effective Lifetime
Fix
3.10.11
Upgrade aiohttp to this version or later

Description

Summary

A memory leak can occur when a request produces a MatchInfoError. This was caused by adding an entry to a cache on each request, due to the building of each MatchInfoError producing a unique cache entry.

Impact

If the user is making use of any middlewares with aiohttp.web then it is advisable to upgrade immediately.

An attacker may be able to exhaust the memory resources of a server by sending a substantial number (100,000s to millions) of such requests.


Patch: https://github.com/aio-libs/aiohttp/commit/bc15db61615079d1b6327ba42c682f758fa96936

Affected versions

PyPI

PackageVulnerableFixed in
aiohttp
>= 3.10.6, < 3.10.11
3.10.11

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

aiohttp PyPI → 3.10.11

pip
pip install --upgrade "aiohttp>=3.10.11"
poetry
poetry add "aiohttp>=3.10.11"
uv
uv add "aiohttp>=3.10.11"

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Attack vector
Network
Attack complexity
Low
Attack requirements
None
Privileges required
None
User interaction
None
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
None
Availability (vulnerable system)
Low
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None

CVSS 3.1 7.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Weakness

CWE-772: Missing Release of Resource after Effective Lifetime

The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.

How to prevent it
  • Requirements: Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, languages such as Java, Ruby, and Lisp perform automatic garbage collection that releases memory for objects that have been deallocated.
  • Implementation: It is good practice to be responsible for freeing all resources you allocate and to be consistent with how and where you free resources in a function. If you allocate resources that you intend to free upon completion of the function, you must be sure to free the resources at all exit points for that function including error conditions.
  • Operation, Architecture and Design: Use resource-limiting settings provided by the operating system or environment. For example, when managing system resources in POSIX, setrlimit() can be used to set limits for certain types of resources, and getrlimit() can determine how many resources are available. However, these functions are not available on all operating systems. When the current levels get close to the maximum that is defined for the application (see CWE-770), then limit the allocation of further resources to privileged users; alternately, begin releasing resources for less-privileged users. While this mitigation may protect the system from attack, it will not necessarily stop attackers from adversely impacting other users. Ensure that the application performs the appropriate error checks and error handling in case resources become unavailable (CWE-703).

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-pqxq-w44r-73xw
AIOHTTP: Pure-Python parser request smuggling
Medium Also affects aiohttp
GHSA-gx76-c99x-2c96
AIOHTTP: Cookie from subdomain can remove Host-Only Scope from existing cookies
Low Also affects aiohttp
GHSA-f9xw-jh8m-3mwq
AIOHTTP: Absolute-form request targets can spoof Request.scheme
Medium Also affects aiohttp
GHSA-9xw5-w5jj-pvcg
AIOHTTP: File descriptor exhaustion in multipart requests
High Also affects aiohttp
GHSA-6cjc-53gc-5rqm
AIOHTTP: Connector pool exhaustion via Max-Age overflow
Medium Also affects aiohttp
GHSA-5wr8-gcqf-gqf3
aiohttp server lacks an initial request/header timeout
High Also affects aiohttp
GHSA-494j-54xm-rwp3
AIOHTTP: Secure attribute not enforced for shared cookie
Medium Also affects aiohttp
GHSA-2g87-pp6c-29x5
aiohttp: Multiple instances of excessive or unbounded memory/CPU use
High Also affects aiohttp
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