Arch Linux Security Advisory ASA-201711-40

Severity: High
Date : 2017-11-30
CVE-ID : CVE-2017-15924
Package : shadowsocks-libev
Type : arbitrary command execution
Remote : No
Link : https://security.archlinux.org/AVG-474

Summary

The package shadowsocks-libev before version 3.1.1-1 is vulnerable to
arbitrary command execution.

Resolution

Upgrade to 3.1.1-1.

pacman -Syu “shadowsocks-libev>=3.1.1-1”

The problem has been fixed upstream in version 3.1.1.

Workaround

None.

Description

In manager.c in ss-manager in shadowsocks-libev before 3.1.1, improper
parsing allows command injection via shell metacharacters in a JSON
configuration request received via 127.0.0.1 UDP traffic, related to
the add_server, build_config, and construct_command_line functions.

Impact

A local attacker could send a specially crafted configuration request
to localhost that, when processed by ss-manager, leads to the execution
of arbitrary commands as the user running ss-manager.

References

http://openwall.com/lists/oss-security/2017/10/13/2
https://github.com/shadowsocks/shadowsocks-libev/commit/c67d275803dc6ea22c558d06b1f7ba9f94cd8de3
https://github.com/shadowsocks/shadowsocks-libev/issues/1734
https://www.x41-dsec.de/lab/advisories/x41-2017-010-shadowsocks-libev/
https://security.archlinux.org/CVE-2017-15924