openvm: Incorrect Calculation of Buffer Size
CVE-2025-46723 is a high-severity incorrect calculation of buffer size vulnerability in openvm from Openvm-org, with a CVSS 4.0 base score of 7.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected openvm versions: = 1.0.0. The record does not name a fixed version, so check the vendor advisory. 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
- Check which version of openvm 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 |
|---|---|---|---|
| Openvm-org | openvm | = 1.0.0 | 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.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- NoneNo loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- HighSerious loss of availability on the vulnerable system.
- Confidentiality (other systems)
- NoneNo loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- NoneNo loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- NoneNo loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (github.com).
Official description
OpenVM is a performant and modular zkVM framework built for customization and extensibility. In version 1.0.0, OpenVM is vulnerable to overflow through byte decomposition of pc in AUIPC chip. A typo results in the highest limb of pc being range checked to 8-bits instead of 6-bits. This results in the if statement never being triggered because the enumeration gives i=0,1,2, when instead the enumeration should give i=1,2,3, leaving pc_limbs[3] range checked to 8-bits instead of 6-bits. This leads to a vulnerability where the pc_limbs decomposition differs from the true pc, which means a malicious prover can make the destination register take a different value than the AUIPC instruction dictates, by making the decomposition overflow the BabyBear field. This issue has been patched in version 1.1.0.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Calculation of Buffer Size
The product does not correctly calculate the size to be used when allocating a buffer.
How developers prevent this class of flaw
- When allocating a buffer for the purpose of transforming, converting, or encoding an input, allocate enough memory to handle the largest possible encoding. For example, in a routine that converts & characters to & for HTML entity encoding, the output buffer needs to be at least 5 times as large as the input buffer.
- Understand the programming language's underlying representation and how it interacts with numeric calculation (CWE-681). Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, not-a-number calculations, and how the language handles numbers that are too large or too small for its underlying representation. Also be careful to account for 32-bit, 64-bit, and other potential differences that may affect the numeric representation.
- Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range.
More Incorrect Calculation of Buffer Size vulnerabilities (CWE-131)
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
Other references
Other vulnerabilities in openvm
- 8.7 High severity
- 8.7 High severity
- 7.5 High severity
Recent Incorrect Calculation of Buffer Size vulnerabilities
- 8.4 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
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