CVE-2021-21257

Out-of-bounds write in RPL-Classic and RPL-Lite

Description

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 rpl_ext_header_srh_update function in the two rpl-ext-header.c modules for RPL-Classic and RPL-Lite respectively. The addr_ptr 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 addr_ptr as destination. The problem has been patched in Contiki-NG 4.6. Users can apply a patch out-of-band as a workaround.

Category

8.2
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.33%
Third-Party Advisory github.com Third-Party Advisory github.com
Affected: contiki-ng contiki-ng
Published at:
Updated at:

References

Link Tags
https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-mvc7-9p4q-c5cm third party advisory patch
https://github.com/contiki-ng/contiki-ng/pull/1431 third party advisory patch

Frequently Asked Questions

What is the severity of CVE-2021-21257?
CVE-2021-21257 has been scored as a high severity vulnerability.
How to fix CVE-2021-21257?
To fix CVE-2021-21257, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-21257 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-21257 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-21257?
CVE-2021-21257 affects contiki-ng contiki-ng.
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