[Racket announcement] Racket Web Server Security Vulnerability

2016-02-08 Thread Sam Tobin-Hochstadt
We recently discovered a serious security vulnerability in the Racket
web server, which can lead to unintended disclosure of files on the
machine running the web server. This vulnerability is fixed in Racket
version 6.4, just released, and we encourage people to upgrade to that
version.

The vulnerability affects web servers that serve static files using
the `#:extra-static-files` option, including the default value of this
option. If you do not use the Racket web serve to serve static files,
or you do so via a mechanism that does not use the `make-url->path`
function, then you are likely not vulnerable. Affected web serves will
allow specially-crafted URLs to access files outside of the specified
paths, potentially exposing any file that the web server process is
able to read.

If you cannot immediately upgrade to version 6.4, we have provided a
package catalog with updated versions of the "web-server-lib" package
for versions of Racket back to 6.0. That catalog is located at

  http://download.racket-lang.org/patches/web-server-1/

To use it to upgrade your Racket installation, add it as a catalog
using `raco pkg config`. To make this process easier, you can download
the Racket script available at
https://gist.github.com/samth/c81e1e2fabc744759970. Then run:

  $ racket add-catalog.rkt
  $ raco pkg update -i web-server-lib

On some systems, this may need to be run with administrator or
super-user privileges, if Racket was installed with those privileges.

If you need advice on updating Racket installations older than version
6.0, please let us know and we will provide them.

To test that your Racket installation is fixed, you can run the
program here: https://gist.github.com/samth/740cc39eb6c0d9bd7bc3

Thanks to Rob Henderson for the discovery of this issue.

Sam, for the Racket team

  Racket Announcements list:
  http://lists.racket-lang.org/announce


[Racket announcement] Racket v6.4

2016-02-08 Thread Ryan Culpepper

Racket version 6.4 is now available from

http://racket-lang.org/

- We fixed a security vulnerability in the web server.  The existing
  web server is vulnerable to a navigation attack if it is also
  enabled to serve files statically; that is, any file readable by
  the web server is accessible remotely. For more information see

http://blog.racket-lang.org/2016/02/racket-web-server-security-vulnerability.html

- DrRacket's scrolling is faster.

- Incremental garbage-collection mode can eliminate long pauses in a
  program. For example, incremental mode is useful for avoiding pauses
  in games and animations.

  Programs must specifically request incremental mode with
  `(collect-garbage 'incremental)`, but libraries such as
  `2htdp/universe` include the request as part of the library's
  implementation.

- The default package catalog is an HTTPS address instead of HTTP, and
  package operations properly validate server certificates when using
  HTTPS.

- Documentation may define their own categories for the manual top-
  level page by using strings, rather than only symbols that name
  pre-defined categories.

- The Racket cheat sheet is included in the main distribution.

- DrRacket is available in Bulgarian, thanks to Alexander Shopov.

- The contract Typed Racket generates for the `Any` type is more
  permissive, allowing more typed/untyped programs to work without
  contract errors.

- Redex supports binding specifications; describe which variables bind
  in which expressions and your metafunctions and reduction relations
  automatically become scope-sensitive. Thanks to Paul Stansifer for
  this improvement.

- All `pict` functions accept `pict-convertible`s. This allows for
  transparent interoperability between `pict` and  libraries like
  `2htdp/image`.

- The `raco profile` and `raco contract-profile` commands provide easy
  access to profiling tools, without requiring program modifications.

Feedback Welcome

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 http://lists.racket-lang.org/announce