Buffer Overflow in telnet.c via crafted client request in Accel-PPP v1.12

CVE ID

CVE-2022-0982

Description

The telnet_input_char function in opt/src/accel-pppd/cli/telnet.c suffers from a memory corruption vulnerability, whereby user input cmdline_len is copied into a fixed buffer b->buf without any bound checks. If the server connects with a malicious client, crafted client requests can remotely trigger this vulnerability.

Tested Versions

Accel-PPP v1.0

Details

Accel PPP is a high performance VPN server application for linux. Its goal is aggregation of various popular VPN techniques to a single application.

When parsing a specifically crafted file, it is possible to cause a memory corruption. This is due to a buffer overflow during a memcpy function:

Timeline

  • 2021-01-04 - Vendor Disclosure
  • 2022-03-15 - Public Release

Credit

Discovered by Eugene Lim and Chloe Ong of Govtech.