A deserialization flaw was discovered in Apache Tomcat's use of a FileStore. An attacker can exploit the flaw if all of the following are true: An attacker is able to control the contents and name of a file on the server. The server is configured to use the PersistenceManager with a FileStore. The PersistenceManager is configured with sessionAttributeValueClassNameFilter="null" (the default unless a SecurityManager is used) or a sufficiently lax filter to allow the attacker-provided object to be deserialized. The attacker knows the relative file path from the storage location used by FileStore to the file the attacker has control over. If all these conditions are true, the attacker can use a specifically crafted request to trigger Remote Code Execution through deserialization of the file under their control.

This flaw affects the following Tomcat versions: 10.0.0-M1 to 10.0.0-M4, 9.0.0.M1 to 9.0.34, 8.5.0 to 8.5.54, and 7.0.0 to 7.0.103.

Upstream commits:

Tomcat 10.0: https://github.com/apache/tomcat/commit/bb33048e3f9b4f2b70e4da2e6c4e34ca89023b1b Tomcat 9.0: https://github.com/apache/tomcat/commit/3aa8f28db7efb311cdd1b6fe15a9cd3b167a2222 Tomcat 8.5: https://github.com/apache/tomcat/commit/ec08af18d0f9ddca3f2d800ef66fe7fd20afef2f Tomcat 7.0: https://github.com/apache/tomcat/commit/53e30390943c18fca0c9e57dbcc14f1c623cfd06

A flaw was found in the Apache Log4j logging library 2.x. when the logging configuration uses a non-default Pattern Layout with a Context Lookup. Attackers with control over Thread Context Map (MDC) input data can craft malicious input data that contains a recursive lookup and can cause Denial of Service.

A flaw was found in Apache Tomcat, where the payload length in a WebSocket frame was not correctly validated. Invalid payload lengths could trigger an infinite loop. Multiple requests with invalid payload lengths could lead to a denial of service. The highest threat from this vulnerability is to system availability.

A vulnerability was found in Hibernate-Validator. The SafeHtml validator annotation fails to properly sanitize payloads consisting of potentially malicious code in HTML comments and instructions. This vulnerability can result in an XSS attack.

Apache Tomcat could allow a remote attacker to execute arbitrary code on the system, caused by a file read/inclusion vulnerability in the AJP connector. By sending a specially-crafted request, an attacker could exploit this vulnerability to read web application files from a vulnerable server and upload malicious JavaServer Pages (JSP) code within a variety of file types and execute arbitrary code on the system.

Note: This vulnerability is known as Ghostcat.

Last updated 25 August 2025

Last updated 2 August 2024

A flaw was found in Apache Tomcat. When responding to new h2c connection requests, Apache Tomcat could duplicate request headers and a limited amount of request body from one request to another meaning user A and user B could both see the results of user A's request. The highest threat from this vulnerability is to data confidentiality.

A flaw was found in Apache Tomcat, where an h2c direct connection did not release the HTTP/1.1 processor after the upgrade to HTTP/2. If a sufficient number of such requests are made, an OutOfMemoryException could occur, leading to a denial of service. The highest threat from this vulnerability is to system availability.

Apache Tomcat is vulnerable to HTTP request smuggling, caused by a flaw when handling unusual Transfer-Encoding HTTP header. By sending a specially-crafted request, an attacker could exploit this vulnerability to poison the web cache, bypass web application firewall protection, and conduct XSS attacks.

Apache Tomcat 10.0.0-M1 to 10.0.6, 9.0.0.M1 to 9.0.46 and 8.5.0 to 8.5.66 did not correctly parse the HTTP transfer-encoding request header in some circumstances leading to the possibility to request smuggling when used with a reverse proxy. Specifically: - Tomcat incorrectly ignored the transfer encoding header if the client declared it would only accept an HTTP/1.0 response; - Tomcat honoured the identify encoding; and - Tomcat did not ensure that, if present, the chunked encoding was the final encoding.

Vulnerability in the Advanced Networking Option component of Oracle Database Server. Supported versions that are affected are 12.1.0.2, 12.2.0.1 and 19c. Difficult to exploit vulnerability allows unauthenticated attacker with network access via Oracle Net to compromise Advanced Networking Option. Successful attacks require human interaction from a person other than the attacker and while the vulnerability is in Advanced Networking Option, attacks may significantly impact additional products. Successful attacks of this vulnerability can result in takeover of Advanced Networking Option. Note: The July 2021 Critical Patch Update introduces a number of Native Network Encryption changes to deal with vulnerability CVE-2021-2351 and prevent the use of weaker ciphers. Customers should review: "Changes in Native Network Encryption with the July 2021 Critical Patch Update" (Doc ID 2791571.1). CVSS 3.1 Base Score 8.3 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H).

A crafted request uri-path can cause modproxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.

In Apache Log4j 2.x before 2.8.2, when using the TCP socket server or UDP socket server to receive serialized log events from another application, a specially crafted binary payload can be sent that, when deserialized, can execute arbitrary code.

Apache Batik 1.13 is vulnerable to server-side request forgery, caused by improper input validation by the NodePickerPanel. By using a specially-crafted argument, an attacker could exploit this vulnerability to cause the underlying server to make arbitrary GET requests.

A carefully crafted request uri-path can cause modproxyuwsgi to read above the allocated memory and crash (DoS). This issue affects Apache HTTP Server versions 2.4.30 to 2.4.48 (inclusive).

A flaw was found in the Apache Batik library, where it is vulnerable to a Server-Side Request Forgery attack (SSRF) via "xlink:href" attributes. This flaw allows an attacker to cause the underlying server to make arbitrary GET requests. The highest threat from this vulnerability is to system integrity.

A flaw was found in Apache tomcat. When the default servlet returned a redirect to a directory (e.g. redirecting to /foo/ when the user requested /foo) a specially crafted URL could be used to cause the redirect to be generated to any URI of the attackers choice.

References:

https://lists.apache.org/thread.html/23134c9b5a23892a205dc140cdd8c9c0add233600f76b313dda6bd75@%3Cannounce.tomcat.apache.org%3E

A vulnerability was found in http/2 where an attacker opens the HTTP/2 window so the peer can send without constraint; however, they leave the TCP window closed so the peer cannot actually write (many of) the bytes on the wire. The attacker then sends a stream of requests for a large response object. Depending on how the servers queue the responses, this can consume excess memory, CPU, or both, potentially leading to a denial of service.

Apache HTTP Server contains a path traversal vulnerability that allows an attacker to perform remote code execution if files outside directories configured by Alias-like directives are not under default require all denied or if CGI scripts are enabled. This CVE ID resolves an incomplete patch for CVE-2021-41773.

Apache HTTP Server contains a path traversal vulnerability that allows an attacker to perform remote code execution if files outside directories configured by Alias-like directives are not under default �require all denied� or if CGI scripts are enabled. The original patch issued under this CVE ID is insufficient, please review remediation information under CVE-2021-42013.

While fuzzing the 2.4.49 httpd, a new null pointer dereference was detected during HTTP/2 request processing, allowing an external source to DoS the server. This requires a specially crafted request. The vulnerability was recently introduced in version 2.4.49. No exploit is known to the project.

An out-of-bounds write in function apescapequotes of httpd allows an unauthenticated remote attacker to crash the server or potentially execute code on the system with the privileges of the httpd user, by providing malicious input to the function.

Impact

When provided with a URL containing many @ characters in the authority component the authority regular expression exhibits catastrophic backtracking causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.

Patches

The issue has been fixed in urllib3 v1.26.5.

References

- CVE-2021-33503 - JVNVU#92413403 (English) - JVNVU#92413403 (Japanese) - urllib3 v1.26.5

For more information If you have any questions or comments about this advisory: Ask in our community Discord Email sethmichaellarson@gmail.com

Apache HTTP Server versions 2.4.20 to 2.4.43. A specially crafted value for the 'Cache-Digest' header in a HTTP/2 request would result in a crash when the server actually tries to HTTP/2 PUSH a resource afterwards. Configuring the HTTP/2 feature via "H2Push off" will mitigate this vulnerability for unpatched servers.

A flaw was found in Apache's HTTP server (httpd) .The modproxyftp module may use uninitialized memory with proxying to a malicious FTP server. The highest threat from this vulnerability is to data confidentiality.

A flaw was found in Apache Tomcat. The HTTP header parsing code used an approach to end-of-line (EOL) parsing that allowed some invalid HTTP headers to be parsed as valid. This led to the possibility of HTTP Request Smuggling if Tomcat was located behind a reverse proxy that incorrectly handled the invalid Transfer-Encoding header in a particular manner. The highest threat with this vulnerability is system availability.

A flaw was found in Apache HTTP Server (httpd) versions 2.4.0 to 2.4.41. Redirects configured with modrewrite that were intended to be self-referential might be fooled by encoded newlines and redirected instead to an unexpected URL within the request URL.

A flaw was found in Apache httpd in versions 2.4.20 to 2.4.43. Logging using the wrong pool by modhttp2 at debug/trace log level may lead to potential crashes and denial of service. The highest threat from this vulnerability is to system availability.

A flaw was found in Apache httpd in versions 2.4.32 to 2.4.46. The uwsgi protocol does not serialize more than 16K of HTTP header leading to resource exhaustion and denial of service. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.