contiki-ng: Uncontrolled Recursion
CVE-2023-29001 is a high-severity uncontrolled recursion vulnerability in contiki-ng, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected contiki-ng versions: <= 4.9; 4.9 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.56% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of contiki-ng you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Contiki-ng | contiki-ng | <= 4.9; 4.9 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.7 | High | CNA (github.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
Contiki-NG is an open-source, cross-platform operating system for IoT devices. The Contiki-NG operating system processes source routing headers (SRH) in its two alternative RPL protocol implementations. The IPv6 implementation uses the results of this processing to determine whether an incoming packet should be forwarded to another host. Because of missing validation of the resulting next-hop address, an uncontrolled recursion may occur in the tcpip_ipv6_output function in the os/net/ipv6/tcpip.c module when receiving a packet with a next-hop address that is a local address. Attackers that have the possibility to send IPv6 packets to the Contiki-NG host can therefore trigger deeply nested recursive calls, which can cause a stack overflow. The vulnerability has not been patched in the current release of Contiki-NG, but is expected to be patched in the next release. The problem can be fixed by applying the patch in Contiki-NG pull request #2264. Users are advised to either apply the patch manually or to wait for the next release. There are no known workarounds for this vulnerability.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Uncontrolled Recursion
The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.
How developers prevent this class of flaw
- Ensure that an end condition will be reached under all logic conditions. The end condition may include checking against the depth of recursion and exiting with an error if the recursion goes too deep. The complexity of the end condition contributes to the effectiveness of this action.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/contiki-ng/contiki-ng/pull/2264Issue Tracking
Other vulnerabilities in contiki-ng
- 8.1 High severity
- 7.1 High severity
- 7.5 High severity
- 7.5 High severity
- 9.6 Critical severity
- 9.6 Critical severity
Recent Uncontrolled Recursion vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
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