CVE-2021-21257: Out-of-bounds write in RPL-Classic and RPL-Lite
Contiki-NG is an open-source, cross-platform operating system for internet of things devices. The RPL-Classic and RPL-Lite implementations in the Contiki-NG operating system versions prior to 4.6 do not validate the address pointer in the RPL source routing header This makes it possible for an attacker to cause out-of-bounds writes with packets injected into the network stack. Specifically, the problem lies in the rplextheadersrhupdate function in the two rpl-ext-header.c modules for RPL-Classic and RPL-Lite respectively. The addrptr variable is calculated using an unvalidated CMPR field value from the source routing header. An out-of-bounds write can be triggered on line 151 in os/net/routing/rpl-lite/rpl-ext-header.c and line 261 in os/net/routing/rpl-classic/rpl-ext-header.c, which contain the following memcpy call with addrptr as destination. The problem has been patched in Contiki-NG 4.6. Users can apply a patch out-of-band as a workaround.
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is CVE-2021-21257?
CVE-2021-21257 is a vulnerability in the RPL-Classic and RPL-Lite implementations in the Contiki-NG operating system versions prior to 4.6.
What is Contiki-NG?
Contiki-NG is an open-source, cross-platform operating system for internet of things devices.
How does CVE-2021-21257 affect Contiki-NG?
CVE-2021-21257 allows an attacker to exploit a vulnerability in the RPL source routing header, potentially compromising the security of Contiki-NG devices running versions prior to 4.6.
What is the severity of CVE-2021-21257?
The severity of CVE-2021-21257 is high, with a severity value of 7.5.
How can I fix CVE-2021-21257?
To fix CVE-2021-21257, it is recommended to update the Contiki-NG operating system to version 4.6 or later.