Apache HTTP Server versions 2.4.0 to 2.4.46 Unprivileged local users can stop httpd on Windows

The version of httpd24 installed on the remote host is prior to 2.4.48-1.92. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS-2021-1514 advisory.

  - Apache HTTP Server versions 2.4.6 to 2.4.46 mod_proxy_wstunnel configured on an URL that is not     necessarily Upgraded by the origin server was tunneling the whole connection regardless, thus allowing for     subsequent requests on the same connection to pass through with no HTTP validation, authentication or     authorization possibly configured. (CVE-2019-17567)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 Unprivileged local users can stop httpd on Windows     (CVE-2020-13938)

  - Apache HTTP Server versions 2.4.41 to 2.4.46 mod_proxy_http can be made to crash (NULL pointer     dereference) with specially crafted requests using both Content-Length and Transfer-Encoding headers,     leading to a Denial of Service (CVE-2020-13950)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Digest nonce can cause a stack overflow in     mod_auth_digest. There is no report of this overflow being exploitable, nor the Apache HTTP Server team     could create one, though some particular compiler and/or compilation option might make it possible, with     limited consequences anyway due to the size (a single byte) and the value (zero byte) of the overflow     (CVE-2020-35452)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Cookie header handled by mod_session can     cause a NULL pointer dereference and crash, leading to a possible Denial Of Service (CVE-2021-26690)

  - In Apache HTTP Server versions 2.4.0 to 2.4.46 a specially crafted SessionHeader sent by an origin server     could cause a heap overflow (CVE-2021-26691)

  - Apache HTTP Server versions 2.4.39 to 2.4.46 Unexpected matching behavior with 'MergeSlashes OFF'     (CVE-2021-30641)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of httpd installed on the remote host is prior to 2.4.48-2. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2021-1674 advisory.

  - Apache HTTP Server versions 2.4.6 to 2.4.46 mod_proxy_wstunnel configured on an URL that is not     necessarily Upgraded by the origin server was tunneling the whole connection regardless, thus allowing for     subsequent requests on the same connection to pass through with no HTTP validation, authentication or     authorization possibly configured. (CVE-2019-17567)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 Unprivileged local users can stop httpd on Windows     (CVE-2020-13938)

  - Apache HTTP Server versions 2.4.41 to 2.4.46 mod_proxy_http can be made to crash (NULL pointer     dereference) with specially crafted requests using both Content-Length and Transfer-Encoding headers,     leading to a Denial of Service (CVE-2020-13950)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Digest nonce can cause a stack overflow in     mod_auth_digest. There is no report of this overflow being exploitable, nor the Apache HTTP Server team     could create one, though some particular compiler and/or compilation option might make it possible, with     limited consequences anyway due to the size (a single byte) and the value (zero byte) of the overflow     (CVE-2020-35452)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Cookie header handled by mod_session can     cause a NULL pointer dereference and crash, leading to a possible Denial Of Service (CVE-2021-26690)

  - In Apache HTTP Server versions 2.4.0 to 2.4.46 a specially crafted SessionHeader sent by an origin server     could cause a heap overflow (CVE-2021-26691)

  - Apache HTTP Server versions 2.4.39 to 2.4.46 Unexpected matching behavior with 'MergeSlashes OFF'     (CVE-2021-30641)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Apache httpd reports :

- moderate: mod_proxy_wstunnel tunneling of non Upgraded connections (CVE-2019-17567)

- moderate: Improper Handling of Insufficient Privileges (CVE-2020-13938)

- low: mod_proxy_http NULL pointer dereference (CVE-2020-13950)

- low: mod_auth_digest possible stack overflow by one nul byte (CVE-2020-35452)

- low: mod_session NULL pointer dereference (CVE-2021-26690)

- low: mod_session response handling heap overflow (CVE-2021-26691)

- moderate: Unexpected URL matching with 'MergeSlashes OFF' (CVE-2021-30641)

- important: NULL pointer dereference on specially crafted HTTP/2 request (CVE-2021-31618)

The version of httpd installed on the remote host is prior to 2.4.48-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2021-1659 advisory.

  - Apache HTTP Server versions 2.4.6 to 2.4.46 mod_proxy_wstunnel configured on an URL that is not     necessarily Upgraded by the origin server was tunneling the whole connection regardless, thus allowing for     subsequent requests on the same connection to pass through with no HTTP validation, authentication or     authorization possibly configured. (CVE-2019-17567)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 Unprivileged local users can stop httpd on Windows     (CVE-2020-13938)

  - Apache HTTP Server versions 2.4.41 to 2.4.46 mod_proxy_http can be made to crash (NULL pointer     dereference) with specially crafted requests using both Content-Length and Transfer-Encoding headers,     leading to a Denial of Service (CVE-2020-13950)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Digest nonce can cause a stack overflow in     mod_auth_digest. There is no report of this overflow being exploitable, nor the Apache HTTP Server team     could create one, though some particular compiler and/or compilation option might make it possible, with     limited consequences anyway due to the size (a single byte) and the value (zero byte) of the overflow     (CVE-2020-35452)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Cookie header handled by mod_session can     cause a NULL pointer dereference and crash, leading to a possible Denial Of Service (CVE-2021-26690)

  - In Apache HTTP Server versions 2.4.0 to 2.4.46 a specially crafted SessionHeader sent by an origin server     could cause a heap overflow (CVE-2021-26691)

  - Apache HTTP Server versions 2.4.39 to 2.4.46 Unexpected matching behavior with 'MergeSlashes OFF'     (CVE-2021-30641)

  - Apache HTTP Server protocol handler for the HTTP/2 protocol checks received request headers against the     size limitations as configured for the server and used for the HTTP/1 protocol as well. On violation of     these restrictions and HTTP response is sent to the client with a status code indicating why the request     was rejected. This rejection response was not fully initialised in the HTTP/2 protocol handler if the     offending header was the very first one received or appeared in a a footer. This led to a NULL pointer     dereference on initialised memory, crashing reliably the child process. Since such a triggering HTTP/2     request is easy to craft and submit, this can be exploited to DoS the server. This issue affected     mod_http2 1.15.17 and Apache HTTP Server version 2.4.47 only. Apache HTTP Server 2.4.47 was never     released. (CVE-2021-31618)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

According to its banner, the version of Apache running on the remote host is 2.4.x prior to 2.4.48. It is, therefore, affected by multiple vulnerabilities:

 - Unexpected <Location> section matching with 'MergeSlashes OFF'. (CVE-2021-30641)

 - mod_auth_digest: possible stack overflow by one nul byte while validating the Digest nonce. (CVE-2020-35452)

 - mod_session: Fix possible crash due to NULL pointer dereference, which could be used to cause a Denial of Service with a malicious backend server and SessionHeader. (CVE-2021-26691)

 - mod_session: Fix possible crash due to NULL pointer dereference, which could be used to cause a Denial of Service. (CVE-2021-26690)

 - mod_proxy_http: Fix possible crash due to NULL pointer dereference, which could be used to cause a Denial of Service. (CVE-2020-13950)

 - Windows: Prevent local users from stopping the httpd process (CVE-2020-13938)

 - mod_proxy_wstunnel, mod_proxy_http: Handle Upgradable protocols end-to-end negotiation. (CVE-2019-17567)

 - mod_http2: Fix a potential NULL pointer dereference. (CVE-2021-31618)

Note that the scanner has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of Apache httpd installed on the remote host is prior to 2.4.47. It is, therefore, affected by multiple vulnerabilities as referenced in the 2.4.47 changelog:

  - Unexpected <Location> section matching with 'MergeSlashes OFF' (CVE-2021-30641)

  - mod_auth_digest: possible stack overflow by one nul byte while validating the Digest nonce. (CVE-2020-35452)

  - mod_session: Fix possible crash due to NULL pointer dereference, which could be used to cause a Denial of Service     with a malicious backend server and SessionHeader. (CVE-2021-26691)

  - mod_session: Fix possible crash due to NULL pointer dereference, which could be used to cause a Denial of Service.
    (CVE-2021-26690)

  - mod_proxy_http: Fix possible crash due to NULL pointer dereference, which could be used to cause a Denial of     Service. (CVE-2020-13950)

  - Windows: Prevent local users from stopping the httpd process (CVE-2020-13938)

  - mod_proxy_wstunnel, mod_proxy_http: Handle Upgradable protocols end-to-end negotiation. (CVE-2019-17567)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
151522	Amazon Linux AMI : httpd24 (ALAS-2021-1514)	Nessus	Amazon Linux Local Security Checks	critical
151272	Amazon Linux 2 : httpd (ALAS-2021-1674)	Nessus	Amazon Linux Local Security Checks	critical
151010	FreeBSD : Apache httpd -- Multiple vulnerabilities (cce76eca-ca16-11eb-9b84-d4c9ef517024)	Nessus	FreeBSD Local Security Checks	critical
150983	Amazon Linux 2 : httpd (ALAS-2021-1659)	Nessus	Amazon Linux Local Security Checks	critical
112806	Apache 2.4.x < 2.4.48 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	critical
150280	Apache 2.4.x < 2.4.47 Multiple Vulnerabilities	Nessus	Web Servers	critical

Detections

Analytics

CVE-2020-13938

medium

Tenable Plugins

critical

critical

critical

critical

critical

critical