Linux kernel (RPL protocol): Reachable Assertion
CVE-2023-2156 is a high-severity reachable assertion vulnerability in Linux kernel (RPL protocol), 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 Linux kernel (RPL protocol) versions: Reproducible on the latest mainline.. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 6.18% chance of exploitation within 30 days, which is in the top 6.39% of all scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux Kernel to 5.10.184 or 5.15.117 or 6.1.34 or 6.2.13, whichever matches your release line, or a later version.
- 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 |
|---|---|---|---|
| Linux kernel (RPL protocol) | Linux kernel (RPL protocol) | Reproducible on the latest mainline. | Not stated |
| Linux | Linux Kernel | 5.7 up to, but not including, 5.10.184; 5.11 up to, but not including, 5.15.117; 5.16 up to, but not including, 6.1.34; 6.2 up to, but not including, 6.2.13; 6.3 up to, but not including, 6.3.8 | 5.10.184, 5.15.117, 6.1.34, 6.2.13, 6.3.8 |
| Red Hat | Enterprise Linux | 9.0 | Not stated |
| Fedora Project | Fedora | 38 | Not stated |
| Debian | Debian Linux | 10.0 | 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.
Official description
A flaw was found in the networking subsystem of the Linux kernel within the handling of the RPL protocol. This issue results from the lack of proper handling of user-supplied data, which can lead to an assertion failure. This may allow an unauthenticated remote attacker to create a denial of service condition on the system.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Reachable Assertion
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.
How developers prevent this class of flaw
- If the assertion statement is required (e.g., for security or reliability), change the invoking code to avoid the conditions that trigger the assertion.
- Consider changing the assertion to some other less fatal error. This might not be easy to implement, since other code may be needed to handle the error.
- Make sensitive open/close operations non-reachable from directly user-controlled data (e.g. open/close resources)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- bugzilla.redhat.com/show_bug.cgi?id=2196292Issue Tracking, Third Party Advisory
- lists.debian.org/debian-lts-announce/2023/08/msg00001.htmlMailing List, Third Party Advisory
- security.netapp.com/advisory/ntap-20230622-0001/Mailing List, Third Party Advisory
- debian.org/security/2023/dsa-5448Third Party Advisory, VDB Entry
- debian.org/security/2023/dsa-5453Third Party Advisory, VDB Entry
- zerodayinitiative.com/advisories/ZDI-23-547/Third Party Advisory, VDB Entry
Other references
- openwall.com/lists/oss-security/2023/05/17/8Mailing List
- openwall.com/lists/oss-security/2023/05/17/9Mailing List
- openwall.com/lists/oss-security/2023/05/18/1Mailing List
- openwall.com/lists/oss-security/2023/05/19/1Mailing List
Recent Reachable Assertion vulnerabilities
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