haproxy: http_get_hdr()/get_ip_from_hdr2() MAX_HDR_HISTORY handling denial of service

HAProxy 1.4 before 1.4.24 and 1.5 before 1.5-dev19, when configured to use hdr_ip or other "hdr_*" functions with a negative occurrence count, allows remote attackers to cause a denial of service (negative array index usage and crash) via an HTTP header with a certain number of values, related to the MAX_HDR_HISTORY variable.

haproxy: request smuggling attack in HTTP/1 header parsing

HAProxy before 2.7.3 may allow a bypass of access control because HTTP/1 headers are inadvertently lost in some situations, aka "request smuggling." The HTTP header parsers in HAProxy may accept empty header field names, which could be used to truncate the list of HTTP headers and thus make some headers disappear after being parsed and processed for HTTP/1.0 and HTTP/1.1. For HTTP/2 and HTTP/3, the impact is limited because the headers disappear before being parsed and processed, as if they had not been sent by the client. The fixed versions are 2.7.3, 2.6.9, 2.5.12, 2.4.22, 2.2.29, and 2.0.31.

haproxy: potential infinite loop condition in the h2_send() may trigger a DoS

HAProxy 2.9.x before 2.9.10, 3.0.x before 3.0.4, and 3.1.x through 3.1-dev6 allows a remote denial of service for HTTP/2 zero-copy forwarding (h2_send loop) under a certain set of conditions, as exploited in the wild in 2024.

haproxy: segfault DoS

An uncontrolled resource consumption vulnerability was discovered in HAProxy which could crash the service. This issue could allow an authenticated remote attacker to run a specially crafted malicious server in an OpenShift cluster. The biggest impact is to availability.

haproxy: data leak via fcgi requests

An information leak vulnerability was discovered in HAProxy 2.1, 2.2 before 2.2.27, 2.3, 2.4 before 2.4.21, 2.5 before 2.5.11, 2.6 before 2.6.8, 2.7 before 2.7.1. There are 5 bytes left uninitialized in the connection buffer when encoding the FCGI_BEGIN_REQUEST record. Sensitive data may be disclosed to configured FastCGI backends in an unexpected way.

haproxy: malformed HTTP header field name can lead to HTTP request/response smuggling

HTTP request/response smuggling vulnerability in HAProxy version 2.7.0, and 2.6.1 to 2.6.7 allows a remote attacker to alter a legitimate user's request. As a result, the attacker may obtain sensitive information or cause a denial-of-service (DoS) condition.

haproxy: untrimmed URI fragments may lead to exposure of confidential data on static servers

HAProxy before 2.8.2 accepts # as part of the URI component, which might allow remote attackers to obtain sensitive information or have unspecified other impact upon misinterpretation of a path_end rule, such as routing index.html#.png to a static server.

haproxy: Proxy forwards malformed empty Content-Length headers

HAProxy through 2.0.32, 2.1.x and 2.2.x through 2.2.30, 2.3.x and 2.4.x through 2.4.23, 2.5.x and 2.6.x before 2.6.15, 2.7.x before 2.7.10, and 2.8.x before 2.8.2 forwards empty Content-Length headers, violating RFC 9110 section 8.6. In uncommon cases, an HTTP/1 server behind HAProxy may interpret the payload as an extra request.

haproxy: Denial of service via set-cookie2 header

A flaw was found in the way HAProxy processed HTTP responses containing the "Set-Cookie2" header. This flaw could allow an attacker to send crafted HTTP response packets which lead to an infinite loop, eventually resulting in a denial of service condition. The highest threat from this vulnerability is availability.

haproxy: request smuggling attack or response splitting via duplicate content-length header

An integer overflow exists in HAProxy 2.0 through 2.5 in htx_add_header that can be exploited to perform an HTTP request smuggling attack, allowing an attacker to bypass all configured http-request HAProxy ACLs and possibly other ACLs.

haproxy: it can lead to a situation with an attacker-controlled HTTP Host header because a mismatch between Host and authority is mishandled

An issue was discovered in HAProxy 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. It can lead to a situation with an attacker-controlled HTTP Host header, because a mismatch between Host and authority is mishandled.

haproxy: an HTTP method name may contain a space followed by the name of a protected resource

An issue was discovered in HAProxy 2.0 before 2.0.24, 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. An HTTP method name may contain a space followed by the name of a protected resource. It is possible that a server would interpret this as a request for that protected resource, such as in the "GET /admin? HTTP/1.1 /static/images HTTP/1.1" example.

haproxy: does not ensure that the scheme and path portions of a URI have the expected characters

An issue was discovered in HAProxy 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. It does not ensure that the scheme and path portions of a URI have the expected characters. For example, the authority field (as observed on a target HTTP/2 server) might differ from what the routing rules were intended to achieve.

haproxy: malformed HTTP/2 requests can lead to out-of-bounds writes

In hpack_dht_insert in hpack-tbl.c in the HPACK decoder in HAProxy 1.8 through 2.x before 2.1.4, a remote attacker can write arbitrary bytes around a certain location on the heap via a crafted HTTP/2 request, possibly causing remote code execution.

haproxy: HTTP/2 implementation vulnerable to intermediary encapsulation attacks

The HTTP/2 implementation in HAProxy before 2.0.10 mishandles headers, as demonstrated by carriage return (CR, ASCII 0xd), line feed (LF, ASCII 0xa), and the zero character (NUL, ASCII 0x0), aka Intermediary Encapsulation Attacks.

haproxy: HTTP request smuggling issue with transfer-encoding header containing an obfuscated "chunked" value

A flaw was found in HAProxy before 2.0.6. In legacy mode, messages featuring a transfer-encoding header missing the "chunked" value were not being correctly rejected. The impact was limited but if combined with the "http-reuse always" setting, it could be used to help construct an HTTP request smuggling attack against a vulnerable component employing a lenient parser that would ignore the content-length header as soon as it saw a transfer-encoding one (even if not entirely valid according to the specification).

headerv2.go in mastercactapus proxyprotocol before 0.0.2, as used in the mastercactapus caddy-proxyprotocol plugin through 0.0.2 for Caddy, allows remote attackers to cause a denial of service (webserver panic and daemon crash) via a crafted HAProxy PROXY v2 request with truncated source/destination address data.

haproxy: DoS via vectors realted to htx_manage_client_side_cookies in proto_htx.c

HAProxy through 2.0.2 allows attackers to cause a denial of service (ha_panic) via vectors related to htx_manage_client_side_cookies in proto_htx.c.

haproxy: weak HMAC keys used to TLS session resumption after reload with rotated keys

HAProxy before 1.9.7 mishandles a reload with rotated keys, which triggers use of uninitialized, and very predictable, HMAC keys. This is related to an include/types/ssl_sock.h error.

haproxy: Mishandling of priority flag in short HEADERS frame by HTTP/2 decoder allows for crash

An out-of-bounds read issue was discovered in the HTTP/2 protocol decoder in HAProxy 1.8.x and 1.9.x through 1.9.0 which can result in a crash. The processing of the PRIORITY flag in a HEADERS frame requires 5 extra bytes, and while these bytes are skipped, the total frame length was not re-checked to make sure they were present in the frame.