mruby/mruby: Out-of-bounds Read
CVE-2022-1427 is a high-severity out-of-bounds read vulnerability in mruby/mruby from Mruby, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists version 3.2 as the first without the flaw, so updating mruby/mruby to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.48% 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
- Update mruby/mruby to 3.2 or a later version.
- Update Mruby to 3.2 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Mruby | mruby/mruby | before 3.2 | 3.2 |
| Mruby | Mruby | before 3.2 | 3.2 |
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- 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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.0 | 7.7 | High | CNA (huntr.dev) |
| CVSS 2.0 | 4.6 | Medium | NVD |
Official description
Out-of-bounds Read in mrb_obj_is_kind_of in in GitHub repository mruby/mruby prior to 3.2. # Impact: Possible arbitrary code execution if being exploited.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/mruby/mruby/commit/a4d97934d51cb88954cc49161dc1d151f64afb6bThird Party Advisory
Technical write-ups (may include proof of concept)
- huntr.dev/bounties/23b6f0a9-64f5-421e-a55f-b5b7a671f301Exploit, Third Party Advisory
Other vulnerabilities in mruby/mruby
- 9.8 Critical severity
Recent Out-of-bounds Read vulnerabilities
- 7.1 High severity
- 8.6 High severity
- 7.8 High severity
- 7.1 High severity
- 7.1 High severity
- 8.8 High severity
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