Vulnerability Details : CVE-2021-21257
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.
Vulnerability category: Memory Corruption
Products affected by CVE-2021-21257
- cpe:2.3:o:contiki-ng:contiki-ng:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-21257
0.11%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 42 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-21257
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
5.0
|
MEDIUM | AV:N/AC:L/Au:N/C:N/I:N/A:P |
10.0
|
2.9
|
NIST | |
|
7.5
|
HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
3.9
|
3.6
|
NIST | |
|
8.2
|
HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L |
3.9
|
4.2
|
GitHub, Inc. |
CWE ids for CVE-2021-21257
-
The product writes data past the end, or before the beginning, of the intended buffer.Assigned by: security-advisories@github.com (Primary)
References for CVE-2021-21257
-
https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-mvc7-9p4q-c5cm
Out-of-bounds write in RPL-Classic and RPL-Lite · Advisory · contiki-ng/contiki-ng · GitHubPatch;Third Party Advisory
-
https://github.com/contiki-ng/contiki-ng/pull/1431
Validate the address pointer in the source routing header by nvt · Pull Request #1431 · contiki-ng/contiki-ng · GitHubPatch;Third Party Advisory
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