When unpacking a tarball that contains a symlink the tar crate may create directories outside of the directory it's supposed to unpack into.

The function errors when it's trying to create a file, but the folders are already created at this point.

use std::{io, io::Result};
use tar::{Archive, Builder, EntryType, Header};

fn main() -> Result<()> {
    let mut buf = Vec::new();

    {
        let mut builder = Builder::new(&mut buf);

        // symlink: parent -> ..
        let mut header = Header::new_gnu();
        header.set_path("symlink")?;
        header.set_link_name("..")?;
        header.set_entry_type(EntryType::Symlink);
        header.set_size(0);
        header.set_cksum();
        builder.append(&header, io::empty())?;

        // file: symlink/exploit/foo/bar
        let mut header = Header::new_gnu();
        header.set_path("symlink/exploit/foo/bar")?;
        header.set_size(0);
        header.set_cksum();
        builder.append(&header, io::empty())?;

        builder.finish()?;
    };

    Archive::new(&*buf).unpack("demo")
}

This has been fixed in https://github.com/alexcrichton/tar-rs/pull/259 and is published as tar 0.4.36. Thanks to Martin Michaelis (@mgjm) for discovering and reporting this, and Nikhil Benesch (@benesch) for the fix!

The git2 and libgit2-sys crates are Rust wrappers around the libgit2 C library. It was discovered that libgit2 1.5.0 and below did not verify SSH host keys when establishing an SSH connection, exposing users of the library to Man-In-the-Middle attacks.

The libgit2 team assigned CVE-2023-22742 to this vulnerability. The following versions of the libgit2-sys Rust crate have been released:

• libgit2-sys 0.14.2, updating the underlying libgit2 C library to version 1.5.1.
• libgit2-sys 0.13.5, updating the underlying libgit2 C library to version 1.4.5.

A new git2 crate version has also been released, 0.16.1. This version only bumps its libgit2-sys dependency to ensure no vulnerable libgit2-sys versions are used, but contains no code changes: if you update the libgit2-sys version there is no need to also update the git2 crate version.

You can learn more about this vulnerability in libgit2's advisory

The remove_dir_all crate is a Rust library that offers additional features over the Rust standard library fs::remove_dir_all function.

It was possible to trick a privileged process doing a recursive delete in an attacker controlled directory into deleting privileged files, on all operating systems.

For instance, consider deleting a tree called 'etc' in a parent directory called 'p'. Between calling remove_dir_all("a") and remove_dir_all("a") actually starting its work, the attacker can move 'p' to 'p-prime', and replace 'p' with a symlink to '/'. Then the privileged process deletes 'p/etc' which is actually /etc, and now your system is broken. There are some mitigations for this exact scenario, such as CWD relative file lookup, but they are not guaranteed - any code using absolute paths will not have that protection in place.

The same attack could be performed at any point in the directory tree being deleted: if 'a' contains a child directory called 'etc', attacking the deletion by replacing 'a' with a link is possible.

The new code in this release mitigates the attack within the directory tree being deleted by using file-handle relative operations: to open 'a/etc', the path 'etc' relative to 'a' is opened, where 'a' is represented by a file descriptor (Unix) or handle (Windows). With the exception of the entry points into the directory deletion logic, this is robust against manipulation of the directory hierarchy, and remove_dir_all will only delete files and directories contained in the tree it is deleting.

The entry path however is a challenge - as described above, there are some potential mitigations, but since using them must be done by the calling code, it is hard to be confident about the security properties of the path based interface.

The new extension trait RemoveDir provides an interface where it is much harder to get it wrong.

somedir.remove_dir_contents("name-of-child").

Callers can then make their own security evaluation about how to securely get a directory handle. That is still not particularly obvious, and we're going to follow up with a helper of some sort (probably in the fs_at crate). Once that is available, the path based entry points will get deprecated.

In the interim, processes that might run with elevated privileges should figure out how to securely identify the directory they are going to delete, to avoid the initial race. Pragmatically, other processes should be fine with the path based entry points : this is the same interface std::fs::remove_dir_all offers, and an unprivileged process running in an attacker controlled directory can't do anything that the attacker can't already do.

When this function was passed an empty string, openssl would attempt to call strlen on it, reading arbitrary memory until it reached a NUL byte.

The libgit2 project fixed three security issues in the 1.7.2 release. These issues are:

• The git_revparse_single function can potentially enter an infinite loop on a well-crafted input, potentially causing a Denial of Service. This function is exposed in the git2 crate via the Repository::revparse_single method.
• The git_index_add function may cause heap corruption and possibly lead to arbitrary code execution. This function is exposed in the git2 crate via the Index::add method.
• The smart transport negotiation may experience an out-of-bounds read when a remote server did not advertise capabilities.

The libgit2-sys crate bundles libgit2, or optionally links to a system libgit2 library. In either case, versions of the libgit2 library less than 1.7.2 are vulnerable. The 0.16.2 release of libgit2-sys bundles the fixed version of 1.7.2, and requires a system libgit2 version of at least 1.7.2.

It is recommended that all users upgrade.