In affected versions, Guzzle gives a transport the request URI as text and supplies the Host header separately. The cURL handlers set CURLOPT_URL to the URI exactly as written and push that Host into CURLOPT_HTTPHEADER; StreamHandler does the same through fopen(). libcurl then parses the authority itself, percent-decoding it and, on an IDN-capable build, applying IDNA mapping, and uses the result to resolve, connect, name the TLS peer and address …
SetCookie::matchesDomain() gives every subdomain of a cookie Domain that cookie unless it recognizes the Domain as an IP literal or a numeric host, and it decides that from the domain's own text, so two spellings a transport reads as an address keep subdomain scope. On 7.15, hexadecimal and mixed-base forms such as 0x7f000001 and 0177.0.0.0x1 go unrecognized while libcurl 8.21.0 reads both as 127.0.0.1, so closing them completes the rule …
When the optional referer redirect setting is enabled, affected versions of RedirectMiddleware can copy the fragment from the referring request URI into a generated Referer header. A URI fragment is the part after #. It is handled locally by the client and is not part of the HTTP request target, so the server handling the original request does not receive it. A generated Referer tells the redirect destination which URI …
In affected versions, Guzzle's built-in CookieJar accepts any number of Set-Cookie header fields from one response, with no limit on the size of each field. When a later request matches the stored cookies, Guzzle places every match into one generated Cookie header without limiting the number of cookies or the total header length. A malicious or compromised server can therefore return many large cookies, causing Guzzle to store attacker-controlled data …
In affected versions, the built-in cURL handlers (CurlHandler and CurlMultiHandler) put every first-class request header in cURL's origin header list (CURLOPT_HTTPHEADER). These handlers are the default when the PHP cURL extension is available. They move Proxy-Authorization to the proxy-only list (CURLOPT_PROXYHEADER) only when Guzzle predicts an HTTP or HTTPS proxy. A "first-class" header is part of the normal request message and can be set on a PSR-7 request, through client …
In affected versions, CookieJar does not preserve whether a response cookie was set without a Domain attribute or with an empty one. A cookie without Domain is host-only and must be returned only to the exact host that set it. Under current cookie processing rules, an empty Domain value is also host-only. Guzzle instead stores the request host in the cookie's Domain field and later applies ordinary domain matching, as …
CookieJar does not restrict a cookie scoped to an IP address to the exact host that set it. When a stored cookie's Domain attribute is an IPv4 literal (Domain=192.168.0.1), a bracketed IPv6 literal (Domain=[::1]), or a bare numeric value that denotes an IPv4 address (Domain=1, which is 0.0.0.1), SetCookie::matchesDomain() applies ordinary subdomain (suffix) matching to it instead of requiring an exact host. The IP-address check inside matchesDomain() is applied only …
The built-in cURL handlers (GuzzleHttp\Handler\CurlHandler and GuzzleHttp\Handler\CurlMultiHandler, used by default whenever the PHP cURL extension is available) accept an https:// proxy — a proxy reached over a TLS-encrypted connection — through the proxy request option, client-level proxy defaults, or proxy environment variables such as http_proxy, https_proxy, HTTPS_PROXY, all_proxy, and ALL_PROXY. When the installed libcurl does not support HTTPS proxies, behavior depends on the libcurl version/build: libcurl older than 7.50.2 silently …
CookieJar incorrectly accepts cookies with a dot-only Domain attribute, such as Domain=., Domain=.., Domain=…, and whitespace-padded variants such as Domain= . . In affected versions, SetCookie::matchesDomain() removes leading dots from the cookie domain, normalizing dot-only values to the empty string; SetCookie::validate() only rejected a strictly empty domain, so these cookies could be stored and the empty normalized domain was treated as matching any request host. An attacker-controlled origin that an …