LoRaMac-node: Off-by-one Error
CVE-2022-39274 is a critical-severity off-by-one error vulnerability in LoRaMac-node from Lora-net, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected LoRaMac-node versions: < 4.7.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.05% chance of exploitation within 30 days, higher than 82% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of LoRaMac-node 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 |
|---|---|---|---|
| Lora-net | LoRaMac-node | < 4.7.0 | 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
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | CNA (github.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
LoRaMac-node is a reference implementation and documentation of a LoRa network node. Versions of LoRaMac-node prior to 4.7.0 are vulnerable to a buffer overflow. Improper size validation of the incoming radio frames can lead to an 65280-byte out-of-bounds write. The function `ProcessRadioRxDone` implicitly expects incoming radio frames to have at least a payload of one byte or more. An empty payload leads to a 1-byte out-of-bounds read of user controlled content when the payload buffer is reused. This allows an attacker to craft a FRAME_TYPE_PROPRIETARY frame with size -1 which results in an 65280-byte out-of-bounds memcopy likely with partially controlled attacker data. Corrupting a large part if the data section is likely to cause a DoS. If the large out-of-bounds write does not immediately crash the attacker may gain control over the execution due to now controlling large parts of the data section. Users are advised to upgrade either by updating their package or by manually applying the patch commit `e851b079`.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Off-by-one Error
A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.
How developers prevent this class of flaw
- When copying character arrays or using character manipulation methods, the correct size parameter must be used to account for the null terminator that needs to be added at the end of the array. Some examples of functions susceptible to this weakness in C include strcpy(), strncpy(), strcat(), strncat(), printf(), sprintf(), scanf() and sscanf().
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- github.com/Lora-net/LoRaMac-node/security/advisories/GHSA-7vv8-73pc-63c2Exploit, Third Party Advisory
Patches and release notes
- github.com/Lora-net/LoRaMac-node/commit/e851b079c82ba1bcf3f4d291ab69a571b0bf458aThird Party Advisory
Recent Off-by-one Error vulnerabilities
- 9.8 Critical severity
- 7.8 High severity
Sudo Heap-Based Buffer Overflow Exploited
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