Varnish Software

Varnish 2.0.6 writes data to a log file without sanitizing non-printable characters, which might allow remote attackers to modify a window's title, or possibly execute arbitrary commands or overwrite files, via an HTTP request containing an escape sequence for a terminal…

In Varnish Cache before 6.6.2 and 7.x before 7.0.2, Varnish Cache 6.0 LTS before 6.0.10, and and Varnish Enterprise (Cache Plus) 4.1.x before 4.1.11r6 and 6.0.x before 6.0.9r4, request smuggling can occur for HTTP/1 connections.

A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then…

Varnish Cache before 7.3.2 and 7.4.x before 7.4.3 (and before 6.0.13 LTS), and Varnish Enterprise 6 before 6.0.12r6, allows credits exhaustion for an HTTP/2 connection control flow window, aka a Broke Window Attack.

An HTTP Request Forgery issue was discovered in Varnish Cache 5.x and 6.x before 6.0.11, 7.x before 7.1.2, and 7.2.x before 7.2.1. An attacker may introduce characters through HTTP/2 pseudo-headers that are invalid in the context of an HTTP/1 request line, causing the Varnish…

In Varnish Cache 7.0.0, 7.0.1, 7.0.2, and 7.1.0, it is possible to cause the Varnish Server to assert and automatically restart through forged HTTP/1 backend responses. An attack uses a crafted reason phrase of the backend response status line. This is fixed in 7.0.3 and 7.1.1.

An issue was discovered in Varnish Cache before 6.0.6 LTS, 6.1.x and 6.2.x before 6.2.3, and 6.3.x before 6.3.2. It occurs when communication with a TLS termination proxy uses PROXY version 2. There can be an assertion failure and daemon restart, which causes a performance loss.

An issue was discovered in Varnish Cache before 6.0.5 LTS, 6.1.x and 6.2.x before 6.2.2, and 6.3.x before 6.3.1. It does not clear a pointer between the handling of one client request and the next request within the same connection. This sometimes causes information to be…

Varnish HTTP cache before 3.0.4: ACL bug

An issue was discovered in Varnish Cache before 6.0.4 LTS, and 6.1.x and 6.2.x before 6.2.1. An HTTP/1 parsing failure allows a remote attacker to trigger an assert by sending crafted HTTP/1 requests. The assert will cause an automatic restart with a clean cache, which makes it…

An issue was discovered in Varnish HTTP Cache 4.0.1 through 4.0.4, 4.1.0 through 4.1.7, 5.0.0, and 5.1.0 through 5.1.2. A wrong if statement in the varnishd source code means that particular invalid requests from the client can trigger an assert, related to an Integer Overflow.…

libvmod-digest before 1.0.3, as used in Varnish Enterprise 6.0.x before 6.0.11r5, has an out-of-bounds memory access during base64 decoding, leading to both authentication bypass and information disclosure; however, the exact attack surface will depend on the particular VCL…

Varnish 3.x before 3.0.7, when used in certain stacked installations, allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via a header line terminated by a \r (carriage return) character in conjunction with multiple Content-Length…

Varnish Cache before 8.0.1 and Varnish Enterprise before 6.0.16r12, in certain unchecked req.url scenarios, mishandle URLs with a path of / for HTTP/1.1, potentially leading to cache poisoning or authentication bypass.

Varnish Cache before 7.6.2 and Varnish Enterprise before 6.0.13r10 allow client-side desync via HTTP/1 requests.

Varnish Enterprise before 6.0.16r12 allows a "workspace overflow" denial of service (daemon panic) for shared VCL. The headerplus.write_req0() function from vmod_headerplus updates the underlying req0, which is normally the original read-only request from which req is derived…

Varnish Cache 9 before 9.0.1 and Varnish Enterprise before 6.0.16r11 allows a "workspace overflow" denial of service (daemon panic) for certain amounts of prefetched data. The setup of an HTTP/2 session starts with a speculative HTTP/1 transport, and upon upgrading to h2 the…

Varnish Enterprise before 6.0.13r13 allows remote attackers to obtain sensitive information via an out-of-bounds read for range requests on ephemeral MSE4 stevedore objects.

Varnish varnish-modules before 0.17.1 allows remote attackers to cause a denial of service (daemon restart) in some configurations. This does not affect organizations that only install the Varnish Cache product; however, it is common to install both Varnish Cache and…

The Command Line Interface (aka Server CLI or administration interface) in the master process in the reverse proxy server in Varnish before 2.1.0 does not require authentication for commands received through a TCP port, which allows remote attackers to (1) execute arbitrary code…

Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorization bypass via a large Content-Length header for a POST request. This affects Varnish Enterprise 6.0.x before 6.0.8r3, and Varnish Cache 5.x and 6.x before 6.5.2, 6.6.x before 6.6.1, and 6.0 LTS…

Varnish before 3.0.5 allows remote attackers to cause a denial of service (child-process crash and temporary caching outage) via a GET request with trailing whitespace characters and no URI.