Dangerous Vulnerability Fixed In Wget

jones_supa writes: A critical flaw has been found and patched in the open source Wget file retrieval utility that is widely used on UNIX systems. The vulnerability is publicly identified as CVE-2014-4877. "It was found that wget was susceptible to a symlink attack which could create arbitrary files, directories or symbolic links and set their permissions when retrieving a directory recursively through FTP," developer Vasyl Kaigorodov writes in Red Hat Bugzilla. A malicious FTP server can stomp over your entire filesystem, tweets HD Moore, chief research officer at Rapid 7, who is the original reporter of the bug.

Comments

Wget

[Anonymous Coward]

Is that the tool you use to download IE ??

Erm... wait, that wasn't right....

rapid7.com metasploit & kb.cert.org advisory

[Anonymous Coward]

- The disclosure is here:

https://community.rapid7.com/c...

- Vulnerability Note VU#685996 (kb.cert.org):

http://www.kb.cert.org/vuls/id...

Re:super user

[caseih]

Yes that's good practice for any command. Though wget is used behind the scenes by, say, opkg on openwrt boxes, which has to run as root since it's unpacking and installing packages. In fact on embedded devices, most everything runs as root there, typically, even if it's a bad idea, and is going to have to change as the internet of things becomes a fact of life. Never thought I'd need to run selinux on an embedded device, but we're to the point now where that's required.

It's good to have this particular bug fixed at least.

Nothing to see here, move along

[gweihir]

Bug found, bug fixed, another venerable tool got even better. This is just business as usual.

Re:Nothing to see here, move along

[gweihir]

Very moderately so. Of course, you should not wget to not trustworthy servers until you have a patched version. But you should not do that anyways, even with the patched version. The biggest risk is still what you get from the server, even if it is confined to its intended place.

Of course, for clueless people using insecure practice, this issue may have some importance. The others are not really at risk and will get the information anyways from the vulnerability information feed of their choice.

Re:super user

[DarkOx]

I was going to make essentially the same comment. Someone is going to jump in and suggest that utilities like that should have their own user account and call sudo or fork and su to start wget as the limited user, and fetch certificates to some specific directory.

Those someones are probably correct, but we all know in practice that rarely happens.

Neat.

[ledow]

Neat trick.

But if you have arbitrary FTP URL's from untrusted sources piped straight into wget on a server you run, you have bigger problems than someone trashing your filesystem or overwriting your /etc/passwd.

Switching to windows

[Anonymous Coward]

Too tired of this kind of crap from the open source community

Re: super user

[undisclosedrecipient]

Root access is the worst case indeed, but it's not a silver bullet if what you really want to protect is accessible by current user. I've seen my share of magical thinking banning root at all costs while in fact confidential data can be grabbed by an exploitable non-root user.

Re:super user

[MouseTheLuckyDog]

Whoosh.

running strings on bad file also unsafe

[throwaway18]

Slightly related;
Lcamtuf writes that that running strings over a maliciously crafted file can probably result in code execution on your system.

http://lcamtuf.blogspot.co.uk/2014/10/psa-dont-run-strings-on-untrusted-files.html

The big picture is nothing new, when you use software, particularly software which is written in C/C++, to process data from untrustworth sources there is a reasonable chance of hard to spot security vulnerabilities.

Re:running strings on bad file also unsafe

[squiggleslash]

Does anyone run "strings" on files they know enough to "trust"? It's essentially a "What the hell is this file? Let me see if it has any useful text strings in it that might give me a hint" tool.