CVE-2023-47627

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. The HTTP parser in AIOHTTP has numerous problems with header parsing, which could lead to request smuggling. This parser is only used when AIOHTTP_NO_EXTENSIONS is enabled (or not using a prebuilt wheel). These bugs have been addressed in commit d5c12ba89 which has been included in release version 3.8.6. Users are advised to upgrade. There are no known workarounds for these issues.

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. The HTTP parser in AIOHTTP has numerous problems with header parsing, which could lead to request smuggling. This parser is only used when AIOHTTP_NO_EXTENSIONS is enabled (or not using a prebuilt wheel). These bugs have been addressed in commit d5c12ba89 which has been included in release version 3.8.6. Users are advised to upgrade. There are no known workarounds for these issues.

Summary

The HTTP parser in AIOHTTP has numerous problems with header parsing, which could lead to request smuggling. This parser is only used when AIOHTTP_NO_EXTENSIONS is enabled (or not using a prebuilt wheel).

Details

Bug 1: Bad parsing of Content-Length values

Description

RFC 9110 says this:

Content-Length = 1*DIGIT

AIOHTTP does not enforce this rule, presumably because of an incorrect usage of the builtin int constructor. Because the int constructor accepts + and - prefixes, and digit-separating underscores, using int to parse CL values leads AIOHTTP to significant misinterpretation.

Examples

GET / HTTP/1.1\r\n
Content-Length: -0\r\n
\r\n
X

GET / HTTP/1.1\r\n
Content-Length: +0_1\r\n
\r\n
X

Suggested action

Verify that a Content-Length value consists only of ASCII digits before parsing, as the standard requires.

Bug 2: Improper handling of NUL, CR, and LF in header values

Description

RFC 9110 says this:

Field values containing CR, LF, or NUL characters are invalid and dangerous, due to the varying ways that implementations might parse and interpret those characters; a recipient of CR, LF, or NUL within a field value MUST either reject the message or replace each of those characters with SP before further processing or forwarding of that message.

AIOHTTP's HTTP parser does not enforce this rule, and will happily process header values containing these three forbidden characters without replacing them with SP.

Examples

GET / HTTP/1.1\r\n
Header: v\x00alue\r\n
\r\n

GET / HTTP/1.1\r\n
Header: v\ralue\r\n
\r\n

GET / HTTP/1.1\r\n
Header: v\nalue\r\n
\r\n

Suggested action

Reject all messages with NUL, CR, or LF in a header value. The translation to space thing, while technically allowed, does not seem like a good idea to me.

Bug 3: Improper stripping of whitespace before colon in HTTP headers

Description

RFC 9112 says this:

No whitespace is allowed between the field name and colon. In the past, differences in the handling of such whitespace have led to security vulnerabilities in request routing and response handling. A server MUST reject, with a response status code of 400 (Bad Request), any received request message that contains whitespace between a header field name and colon.

AIOHTTP does not enforce this rule, and will simply strip any whitespace before the colon in an HTTP header.

Example

GET / HTTP/1.1\r\n
Content-Length : 1\r\n
\r\n
X

Suggested action

Reject all messages with whitespace before a colon in a header field, as the standard requires.

PoC

Example requests are embedded in the previous section. To reproduce these bugs, start an AIOHTTP server without llhttp (i.e. AIOHTTP_NO_EXTENSIONS=1) and send the requests given in the previous section. (e.g. by printfing into nc)

Impact

Each of these bugs can be used for request smuggling.

Async http client/server framework (asyncio).

Security Fix(es):

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. The HTTP parser in AIOHTTP has numerous problems with header parsing, which could lead to request smuggling. This parser is only used when AIOHTTP_NO_EXTENSIONS is enabled (or not using a prebuilt wheel). These bugs have been addressed in commit d5c12ba89 which has been included in release version 3.8.6. Users are advised to upgrade. There are no known workarounds for these issues.(CVE-2023-47627)

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. 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. The vulnerability occurs only if the attacker can control the HTTP method (GET, POST etc.) of the request. If the attacker can control the HTTP version of the request it will be able to modify the request (request smuggling). This issue has been patched in version 3.9.0.(CVE-2023-49082)

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. 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 reading a file 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. Disabling follow_symlinks and using a reverse proxy are encouraged mitigations. Version 3.9.2 fixes this issue.(CVE-2024-23334)

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. Security-sensitive parts of the Python HTTP parser retained minor differences in allowable character sets, that must trigger error handling to robustly match frame boundaries of proxies in order to protect against injection of additional requests. Additionally, validation could trigger exceptions that were not handled consistently with processing of other malformed input. Being more lenient than internet standards require could, depending on deployment environment, assist in request smuggling. The unhandled exception could cause excessive resource consumption on the application server and/or its logging facilities. This vulnerability exists due to an incomplete fix for CVE-2023-47627. Version 3.9.2 fixes this vulnerability.(CVE-2024-23829)

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. A XSS vulnerability exists on index pages for static file handling. This vulnerability is fixed in 3.9.4. We have always recommended using a reverse proxy server (e.g. nginx) for serving static files. Users following the recommendation are unaffected. Other users can disable show_index if unable to upgrade.(CVE-2024-27306)

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. In affected versions an attacker can send a specially crafted POST (multipart/form-data) request. When the aiohttp server processes it, the server will enter an infinite loop and be unable to process any further requests. An attacker can stop the application from serving requests after sending a single request. This issue has been addressed in version 3.9.4. Users are advised to upgrade. Users unable to upgrade may manually apply a patch to their systems. Please see the linked GHSA for instructions.(CVE-2024-30251)

Async http client/server framework (asyncio).

Security Fix(es):

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. The HTTP parser in AIOHTTP has numerous problems with header parsing, which could lead to request smuggling. This parser is only used when AIOHTTP_NO_EXTENSIONS is enabled (or not using a prebuilt wheel). These bugs have been addressed in commit d5c12ba89 which has been included in release version 3.8.6. Users are advised to upgrade. There are no known workarounds for these issues.(CVE-2023-47627)

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. 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. The vulnerability occurs only if the attacker can control the HTTP method (GET, POST etc.) of the request. If the attacker can control the HTTP version of the request it will be able to modify the request (request smuggling). This issue has been patched in version 3.9.0.(CVE-2023-49082)

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. Security-sensitive parts of the Python HTTP parser retained minor differences in allowable character sets, that must trigger error handling to robustly match frame boundaries of proxies in order to protect against injection of additional requests. Additionally, validation could trigger exceptions that were not handled consistently with processing of other malformed input. Being more lenient than internet standards require could, depending on deployment environment, assist in request smuggling. The unhandled exception could cause excessive resource consumption on the application server and/or its logging facilities. This vulnerability exists due to an incomplete fix for CVE-2023-47627. Version 3.9.2 fixes this vulnerability.(CVE-2024-23829)

Async http client/server framework (asyncio).

Security Fix(es):

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. The HTTP parser in AIOHTTP has numerous problems with header parsing, which could lead to request smuggling. This parser is only used when AIOHTTP_NO_EXTENSIONS is enabled (or not using a prebuilt wheel). These bugs have been addressed in commit d5c12ba89 which has been included in release version 3.8.6. Users are advised to upgrade. There are no known workarounds for these issues.(CVE-2023-47627)

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. 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. The vulnerability occurs only if the attacker can control the HTTP method (GET, POST etc.) of the request. If the attacker can control the HTTP version of the request it will be able to modify the request (request smuggling). This issue has been patched in version 3.9.0.(CVE-2023-49082)

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. Security-sensitive parts of the Python HTTP parser retained minor differences in allowable character sets, that must trigger error handling to robustly match frame boundaries of proxies in order to protect against injection of additional requests. Additionally, validation could trigger exceptions that were not handled consistently with processing of other malformed input. Being more lenient than internet standards require could, depending on deployment environment, assist in request smuggling. The unhandled exception could cause excessive resource consumption on the application server and/or its logging facilities. This vulnerability exists due to an incomplete fix for CVE-2023-47627. Version 3.9.2 fixes this vulnerability.(CVE-2024-23829)

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. The HTTP parser in AIOHTTP has numerous problems with header parsing, which could lead to request smuggling. This parser is only used when AIOHTTP_NO_EXTENSIONS is enabled (or not using a prebuilt wheel). These bugs have been addressed in commit d5c12ba89 which has been included in release version 3.8.6. Users are advised to upgrade. There are no known workarounds for these issues.

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. The HTTP parser in AIOHTTP has numerous problems with header parsing, which could lead to request smuggling. This parser is only used when AIOHTTP_NO_EXTENSIONS is enabled (or not using a prebuilt wheel). These bugs have been addressed in commit d5c12ba89 which has been included in release version 3.8.6. Users are advised to upgrade. There are no known workarounds for these issues.

TuxCare rebuilt aiohttp to address 2 CVEs. Fixed in 3.8.5.post1+tuxcare.

TuxCare rebuilt aiohttp to address 1 CVE. Fixed in 3.8.1.post1+tuxcare.

TuxCare rebuilt orjson to address 2 CVEs. Fixed in 3.8.5.post1+tuxcare.

TuxCare rebuilt aiohttp to address 2 CVEs. Fixed in 3.8.4.post15+tuxcare.

These are all security issues fixed in the python310-aiohttp-3.9.0-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the python313-aiohttp-3.14.3-1.1 package on the GA media of openSUSE Tumbleweed.

This update for python-aiohttp, python-time-machine fixes the following issues:

python-aiohttp was updated to version 3.9.3:

• Fixed backwards compatibility breakage (in 3.9.2) of ssl parameter when set outside of ClientSession (e.g. directly in TCPConnector)
• Improved test suite handling of paths and temp files to consistently use pathlib and pytest fixtures.

From version 3.9.2 (bsc#1219341, CVE-2024-23334, bsc#1219342, CVE-2024-23829):

• Fixed server-side websocket connection leak.
• Fixed web.FileResponse doing blocking I/O in the event loop.
• Fixed double compress when compression enabled and compressed file exists in server file responses.
• Added runtime type check for ClientSession timeout parameter.
• Fixed an unhandled exception in the Python HTTP parser on header lines starting with a colon.
• Improved validation of paths for static resources requests to the server.
• Added support for passing :py:data:True to ssl parameter in ClientSession while deprecating :py:data:None.
• Fixed an unhandled exception in the Python HTTP parser on header lines starting with a colon.
• Fixed examples of fallback_charset_resolver function in the :doc:client_advanced document.
• The Sphinx setup was updated to avoid showing the empty changelog draft section in the tagged release documentation builds on Read The Docs.
• The changelog categorization was made clearer. The contributors can now mark their fragment files more accurately.
• Updated :ref:contributing/Tests coverage <aiohttp-contributing> section to show how we use codecov.
• Replaced all tmpdir fixtures with tmp_path in test suite.

• Disable broken tests with openssl 3.2 and python < 3.11 bsc#1217782

update to 3.9.1:

• Fixed importing aiohttp under PyPy on Windows.
• Fixed async concurrency safety in websocket compressor.
• Fixed ClientResponse.close() releasing the connection instead of closing.
• Fixed a regression where connection may get closed during upgrade. -- by :user:Dreamsorcerer
• Fixed messages being reported as upgraded without an Upgrade header in Python parser. -- by :user:Dreamsorcerer

update to 3.9.0: (bsc#1217684, CVE-2023-49081, bsc#1217682, CVE-2023-49082)

• Introduced AppKey for static typing support of Application storage.
• Added a graceful shutdown period which allows pending tasks to complete before the application's cleanup is called.
• Added handler_cancellation_ parameter to cancel web handler on client disconnection.
• This (optionally) reintroduces a feature removed in a previous release.
• Recommended for those looking for an extra level of protection against denial-of-service attacks.
• Added support for setting response header parameters max_line_size and max_field_size.
• Added auto_decompress parameter to ClientSession.request to override ClientSession._auto_decompress.
• Changed raise_for_status to allow a coroutine.
• Added client brotli compression support (optional with runtime check).
• Added client_max_size to BaseRequest.clone() to allow overriding the request body size. -- :user:anesabml.
• Added a middleware type alias aiohttp.typedefs.Middleware.
• Exported HTTPMove which can be used to catch any redirection request that has a location -- :user:dreamsorcerer.
• Changed the path parameter in web.run_app() to accept a pathlib.Path object.
• Performance: Skipped filtering CookieJar when the jar is empty or all cookies have expired.
• Performance: Only check origin if insecure scheme and there are origins to treat as secure, in CookieJar.filter_cookies().
• Performance: Used timestamp instead of datetime to achieve faster cookie expiration in CookieJar.
• Added support for passing a custom server name parameter to HTTPS connection.
• Added support for using Basic Auth credentials from :file:.netrc file when making…

Ben Kallus discovered that AIOHTTP did not correctly parse HTTP headers. A remote attacker could possibly use this issue to perform request smuggling. This issue only affected Ubuntu 20.04 LTS and Ubuntu 22.04 LTS. (CVE-2023-47627)

Ivan Novikov discovered that AIOHTTP did not properly validate certain inputs. A remote attacker could possibly use this issue to perform request smuggling. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS and Ubuntu 22.04 LTS. (CVE-2023-49081, CVE-2023-49082)

Paul J. Dorn discovered that AIOHTTP did not properly validate certain inputs. A remote attacker could possibly use this issue to perform request smuggling. This issue only affected Ubuntu 20.04 LTS, Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2024-23829)

Takeshi Kaneko discovered that AIOHTTP did not properly sanitize certain inputs. A remote attacker could possibly use this issue to perform a cross-site scripting (XSS) attack. (CVE-2024-27306)

It was discovered that AIOHTTP did not correctly handle certain POST requests. A remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 20.04 LTS, Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2024-30251)

Jeppe Bonde Weikop discovered that AIOHTTP did not correctly handle parsing newlines in certain inputs. A remote attacker could possibly use this issue to perform request smuggling. (CVE-2024-52304)