Bareiron: Write-what-where Condition
CVE-2025-69809 is a critical-severity write-what-where condition vulnerability in Bareiron from P2r3, 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 Bareiron versions: 2025-09-16. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.59% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Bareiron you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from NVD's product matching. 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 CISA (ADP).
Official description
A write-what-where condition in p2r3 Bareiron commit 8e4d40 allows unauthenticated attackers to write arbitrary values to memory, enabling arbitrary code execution via a crafted packet.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Write-what-where Condition
Any condition where the attacker has the ability to write an arbitrary value to an arbitrary location, often as the result of a buffer overflow.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
- Use OS-level preventative functionality integrated after the fact. Not a complete solution.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- github.com/vmpr0be/bareiron-vr/blob/main/CVE-2025-69809.mdThird Party Advisory
Other references
- github.com/p2r3/bareironProduct
Other vulnerabilities in Bareiron
- 9.1 Critical severity
- 7.5 High severity
- 7.5 High severity
Recent Write-what-where Condition vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 7.8 High severity
- 8.2 High severity
- 8.1 High severity
- 8.8 High severity
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