HTTP::Body versions before 1.24_01 for Perl allow memory exhaustion via unbounded buffering of chunked request bodies
HTTP::Body versions before 1.24_01 for Perl allow memory exhaustion via unbounded buffering of chunked request bodies.
In chunked mode, used when no content length is given, add() holds each chunk in memory until all of it has arrived. A line that is not a chunk-size line, a size line without CRLF, or a size too large to fit an integer leaves the parser waiting forever, and every later add() grows the buffer.
A remote attacker can exhaust memory in applications that pass chunked request bodies to HTTP::Body.
HTTP::Body versions before 1.24_01 for Perl allow CPU exhaustion via regex backtracking on the filename of a multipart upload
HTTP::Body versions before 1.24_01 for Perl allow CPU exhaustion via regex backtracking on the filename of a multipart upload.
For every file part, the multipart parser finds the suffix of the uploaded filename by matching the default $basename_regexp, qr/[^.]+(\.[^\\\/]+)$/, against the whole basename. A basename made of many dots and ending in a backslash makes the regex backtrack in time quadratic in its length.
A remote attacker can exhaust CPU with one request, as a basename of about 32 KB takes several seconds to match and every file part is matched separately.
HTTP::Body versions before 1.23_01 for Perl lose track of chunk boundaries in chunked request bodies when a read ends inside a chunk
HTTP::Body versions before 1.23_01 for Perl lose track of chunk boundaries in chunked request bodies when a read ends inside a chunk.
In chunked mode, used when no content length is given, add() treats a chunk as complete once the buffer is as long as the chunk's declared size, but the buffer still holds the chunk-size line. When a read ends in the last bytes of a chunk, add() takes the chunk short and parses the leftover data as the next chunk-size line.
A remote attacker can make a chunked body never complete, hanging a server that reads until the body is done, and may make it complete early, leaving the remaining bytes to be read as the
HTTP::Body versions before 1.23_01 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies
HTTP::Body versions before 1.23_01 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies.
In chunked mode, used when no content length is given, add() matches each chunk-size line with `/^([\da-fA-F]+).*\x0D\x0A/`. On a line of hex digits whose first LF has no CR before it, the digits and `.*` backtrack against each other, so a single add() takes time quadratic in the line's length. Nothing limits how long the line can be.
A remote attacker can exhaust CPU in applications that pass chunked request bodies to HTTP::Body.
HTTP::Body versions before 1.23_01 for Perl drop mixed-case percent escapes from urlencoded form fields instead of decoding them
HTTP::Body versions before 1.23_01 for Perl drop mixed-case percent escapes from urlencoded form fields instead of decoding them.
The decode table holds only the all-lowercase and all-uppercase spelling of each hex pair, while the escape pattern matches either case. An escape such as %aB finds no entry and is replaced with nothing, joining the bytes on either side. Hex digits in percent escapes are case-insensitive, and conforming decoders return the byte.
A remote attacker can send a field name or value that a conforming decoder in front of the application reads differently, so that pass%aBword reaches the application as password.
HTTP::Body versions before 1.23_01 for Perl allow memory exhaustion via an unbounded multipart part header block
HTTP::Body versions before 1.23_01 for Perl allow memory exhaustion via an unbounded multipart part header block.
The multipart parser takes everything up to the first blank line after a boundary as the part's header block, with no limit on its size or number of lines. Every line is stored in the part's header hash, so a block of short lines costs about 60 bytes of memory per input byte.
A remote attacker can exhaust worker memory with a single request.
HTTP::Body versions before 1.23_01 for Perl allow CPU exhaustion via quadratic rescanning of a multipart body with a missing or malformed boundary
HTTP::Body versions before 1.23_01 for Perl allow CPU exhaustion via quadratic rescanning of a multipart body with a missing or malformed boundary.
Before the first part, and between parts, the multipart parser searches the whole buffered body for the next boundary. On a miss it keeps everything and searches again from the start when the next chunk arrives. A body with no boundary, or with a delimiter followed by neither CRLF nor "--", is therefore rescanned on every chunk, taking time quadratic in its size.
A remote attacker can exhaust worker CPU with a few such requests.
HTTP::Body versions before 1.23_01 for Perl leave the temporary file of an incomplete multipart upload on disk
HTTP::Body versions before 1.23_01 for Perl leave the temporary file of an incomplete multipart upload on disk.
The multipart parser creates a temporary file as soon as a file part starts, but adds it to the upload list only when the part completes. Uploads are only ever deleted from that list, by the cleanup option or by the caller, so a body that ends inside a file part leaves its temporary file where nothing can find it.
A remote attacker can fill the temporary directory by repeating such requests, leaving one file behind for each.
HTTP::Body versions before 1.23_01 for Perl allow memory and temporary file exhaustion via an unlimited number of form fields and multipart parts
HTTP::Body versions before 1.23_01 for Perl allow memory and temporary file exhaustion via an unlimited number of form fields and multipart parts.
The urlencoded parser splits the whole body on its separators at once, creating one scalar per separator before any field is stored. This costs about 90 bytes of memory per separator byte. The multipart parser creates a temporary file for every part that carries a filename. Neither parser limits how many fields or parts a body may hold.
A remote attacker can exhaust worker memory with a body made of separators, or create thousands of temporary files with one request of small file parts.
HTTP::Body::Multipart in the HTTP-Body module for Perl (1.07 through 1.22, before 1.23) uses the part of the uploaded file's name after the first "." character as the suffix of a temporary file, which makes it easier for remote attackers to conduct attacks by leveraging subsequent behavior that may assume the suffix is well-formed.