PT-2021-3712 · Apache+3 · Apache Http Server+4
Published
2021-04-22
·
Updated
2024-05-01
·
CVE-2021-31618
CVSS v2.0
7.8
High
| Vector | AV:N/AC:L/Au:N/C:N/I:N/A:C |
Name of the Vulnerable Software and Affected Versions
Apache HTTP Server versions 2.4.47
mod http2 version 1.15.17
Description
The issue is related to the HTTP/2 protocol handler in the Apache HTTP Server, which checks received request headers against size limitations. If these restrictions are violated, an HTTP response is sent to the client with a status code indicating why the request was rejected. However, the rejection response was not fully initialized in the HTTP/2 protocol handler under certain conditions, leading to a NULL pointer dereference and crashing the child process. This can be exploited to cause a denial-of-service (DoS) attack on the server by sending a specially crafted HTTP/2 request.
Recommendations
For mod http2 version 1.15.17, consider disabling the HTTP/2 protocol handler until a patch is available.
For Apache HTTP Server version 2.4.47, since it was never released, no specific action is required for this version.
As a temporary workaround, consider restricting access to the HTTP/2 protocol handler to minimize the risk of exploitation.
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
DoS
NULL Pointer Dereference
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Weakness Enumeration
Related Identifiers
Affected Products
Alt Linux
Apache Http Server
Astra Linux
Suse
Mod Http2