VulnerabilityPublished 30 May 2025Updated 4 Feb 2026

CVE-2024-23334: aio-libs aiohttp · Path Traversal

Affects aio-libs aiohttpSource CVE Database V5

Public exploit available (Exploit-DB) · 76% EPSS · CVSS 5.9 Medium : upgrade to 3.9.2 as a priority.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

5.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 76.8% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.9.2

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 30 May 2025
Detectable: evidence found.
nuclei template: aiohttp - Directory Traversal
Weaponised: evidence found.
1 Exploit-DB entry, 250 days after disclosure
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

CVE ID reserved
by GitHub, Inc.
15 Jan 202415:19 UTC, 1.4 years before disclosure
CVE published
on cve.org
30 May 202519:44 UTC, t = 0
In Threat Radar
record ingested
30 May 202519:44 UTC, 1 minute after disclosure
First Exploit-DB entry (opens in a new tab)
aiohttp 3.9.1 - directory traversal PoC
4 Feb 2026, 250 days after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade aio-libs aiohttp to 3.9.2.

Affected software

Product	Affected	Fixed in
PyPIaiohttp`pkg:pypi/aiohttp`Other threats	Affected <3.9.2	Fixed in 3.9.2

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade aiohttp to version 3.9.2 or later immediately to apply the official fix that enforces proper path validation when 'follow_symlinks' is enabled.
Disable the 'follow_symlinks' option unless absolutely necessary, as this is the primary vector for exploitation.
Implement a reverse proxy (e.g., Nginx, Apache) in front of aiohttp servers to restrict access to static file routes and enforce additional access controls.
Conduct a thorough audit of all aiohttp static file configurations to ensure no unintended symbolic links or directory traversal paths exist.
Monitor web server logs for suspicious requests attempting to access files outside the static root directory.
Educate development and operations teams about secure configuration practices for serving static content in aiohttp.
If disabling 'follow_symlinks' is not feasible, consider implementing custom middleware to validate requested paths rigorously before serving files.
Review and update incident response plans to include scenarios involving unauthorized file access via path traversal.

Description

### Summary Improperly configuring static resource resolution in aiohttp when used as a web server can result in the unauthorized reading of arbitrary files on the system. ### Details When using aiohttp as a web server and configuring static routes, it is necessary to specify the root path for static files. Additionally, the option 'follow_symlinks' can be used to determine whether to follow symbolic links outside the static root directory. When 'follow_symlinks' is set to True, there is no validation to check if a given file path is within the root directory.This can lead to directory traversal vulnerabilities, resulting in unauthorized access to arbitrary files on the system, even when symlinks are not present. i.e. An application is only vulnerable with setup code like: ``` app.router.add_routes([ web.static("/static", "static/", follow_symlinks=True), # Remove follow_symlinks to avoid the vulnerability ]) ``` ### Impact This is a directory traversal vulnerability with CWE ID 22. When using aiohttp as a web server and enabling static resource resolution with `follow_symlinks` set to True, it can lead to this vulnerability. This vulnerability has been present since the introduction of the `follow_symlinks` parameter. ### Workaround Even if upgrading to a patched version of aiohttp, we recommend following these steps regardless. If using `follow_symlinks=True` outside of a restricted local development environment, disable the option immediately. This option is NOT needed to follow symlinks which point to a location _within_ the static root directory, it is _only_ intended to allow a symlink to break out of the static directory. Even with this CVE fixed, there is still a substantial risk of misconfiguration when using this option on a server that accepts requests from remote users. Additionally, aiohttp has always recommended using a reverse proxy server (such as nginx) to handle static resources and _not_ to use these static resources in aiohttp for production environments. Doing so also protects against this vulnerability, and is why we expect the number of affected users to be very low. ----- Patch: https://github.com/aio-libs/aiohttp/pull/8079/files

Impact

For European organizations, this vulnerability poses a significant risk to the confidentiality of sensitive data hosted on aiohttp-based web servers. Attackers exploiting this flaw can access arbitrary files, potentially exposing configuration files, credentials, or proprietary information. This risk is particularly acute for organizations serving static content via aiohttp with 'follow_symlinks' enabled, including web applications, APIs, and internal tools. While the vulnerability does not affect data integrity or system availability, unauthorized file disclosure can lead to further attacks such as credential theft or lateral movement. The medium CVSS score reflects the need for timely remediation but indicates that exploitation requires some conditions (e.g., enabling 'follow_symlinks'). European entities in sectors like finance, healthcare, and government, which often handle sensitive data and rely on Python-based infrastructure, are especially vulnerable. Failure to patch could result in data breaches, regulatory non-compliance (e.g., GDPR), and reputational damage.

Summary

CVE-2024-23334 is a path traversal vulnerability classified under CWE-22 found in aiohttp, a popular asynchronous HTTP client/server framework for Python's asyncio. The vulnerability manifests when aiohttp is used as a web server to serve static files and the 'follow_symlinks' option is enabled. This option allows the server to follow symbolic links outside the configured static root directory. However, aiohttp versions prior to 3.9.2 lack proper validation to ensure that file requests remain confined within the root directory when following symlinks. Consequently, an attacker can craft HTTP requests that exploit this flaw to access arbitrary files on the server's filesystem, bypassing intended directory restrictions. Notably, this vulnerability can be exploited even if no symlinks are present, due to insufficient path validation logic. The vulnerability does not require authentication or user interaction, increasing its risk profile. The CVSS v3.1 score is 5.9, reflecting a medium severity with high confidentiality impact but no effect on integrity or availability. No known exploits have been reported in the wild as of the publication date. The issue was addressed in aiohttp version 3.9.2 by adding proper path validation to prevent directory traversal when 'follow_symlinks' is enabled. Recommended mitigations include disabling the 'follow_symlinks' option if not necessary, upgrading to the patched version, and using reverse proxies to limit direct access to static file routes.

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #6OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
Implementation · Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.3.1 (opens in a new tab)
Attack patterns
Path Traversal (opens in a new tab)
Using Slashes and URL Encoding Combined to Bypass Validation Logic (opens in a new tab)
Manipulating Web Input to File System Calls (opens in a new tab)
Using Escaped Slashes in Alternate Encoding (opens in a new tab)
Using Slashes in Alternate Encoding (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

Timeline

What to do

Affected software

Description

AI analysisMachine-generated, updated 5 Feb 2026, 08:08 UTC

Public exploits and detection1 Exploit-DB entry, a Nuclei detection template

WeaknessesCWE-22

Technical details

References

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