Applications that use Wget to access a remote resource using shorthand URLs and pass arbitrary user credentials in the URL are vulnerable. In these cases attackers can enter crafted credentials which will cause Wget to access an arbitrary host.

url.c in GNU Wget through 1.24.5 mishandles semicolons in the userinfo subcomponent of a URI, and thus there may be insecure behavior in which data that was supposed to be in the userinfo subcomponent is misinterpreted to be part of the host subcomponent.

GNU Wget through 1.21.1 does not omit the Authorization header upon a redirect to a different origin, a related issue to CVE-2018-1000007.

Buffer overflow in GNU Wget 1.20.1 and earlier allows remote attackers to cause a denial-of-service (DoS) or may execute an arbitrary code via unspecified vectors.

set_file_metadata in xattr.c in GNU Wget before 1.20.1 stores a file's origin URL in the user.xdg.origin.url metadata attribute of the extended attributes of the downloaded file, which allows local users to obtain sensitive information (e.g., credentials contained in the URL) by reading this attribute, as demonstrated by getfattr. This also applies to Referer information in the user.xdg.referrer.url metadata attribute. According to 2016-07-22 in the Wget ChangeLog, user.xdg.origin.url was partially based on the behavior of fwrite_xattr in tool_xattr.c in curl.

GNU Wget before 1.19.5 is prone to a cookie injection vulnerability in the resp_new function in http.c via a \r\n sequence in a continuation line.

The retr.c:fd_read_body() function is called when processing OK responses. When the response is sent chunked in wget before 1.19.2, the chunk parser uses strtol() to read each chunk's length, but doesn't check that the chunk length is a non-negative number. The code then tries to read the chunk in pieces of 8192 bytes by using the MIN() macro, but ends up passing the negative chunk length to retr.c:fd_read(). As fd_read() takes an int argument, the high 32 bits of the chunk length are discarded, leaving fd_read() with a completely attacker controlled length argument. The attacker can corrupt malloc metadata after the allocated buffer.

The http.c:skip_short_body() function is called in some circumstances, such as when processing redirects. When the response is sent chunked in wget before 1.19.2, the chunk parser uses strtol() to read each chunk's length, but doesn't check that the chunk length is a non-negative number. The code then tries to skip the chunk in pieces of 512 bytes by using the MIN() macro, but ends up passing the negative chunk length to connect.c:fd_read(). As fd_read() takes an int argument, the high 32 bits of the chunk length are discarded, leaving fd_read() with a completely attacker controlled length argument.

CRLF injection vulnerability in the url_parse function in url.c in Wget through 1.19.1 allows remote attackers to inject arbitrary HTTP headers via CRLF sequences in the host subcomponent of a URL.

Race condition in wget 1.17 and earlier, when used in recursive or mirroring mode to download a single file, might allow remote servers to bypass intended access list restrictions by keeping an HTTP connection open.