CVE-2021-40507
An issue was discovered in the ALU unit of the OR1200 (aka OpenRISC 1200) processor 2011-09-10...
An issue was discovered in the ALU unit of the OR1200 (aka OpenRISC 1200) processor 2011-09-10 through 2015-11-11. The overflow flag is not being updated correctly for the subtract instruction, which results in an incorrect value in the overflow flag. Any software that relies on this flag may experience corruption in execution.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in the ALU unit of the OR1200 (aka OpenRISC 1200) processor 2011-09-10 through 2015-11-11. The overflow flag is not being updated correctly for the subtract instruction, which results in an incorrect value in the overflow flag. Any software that relies on this flag may experience corruption in execution.
- Record
CVE-2021-40507- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-287
- Updated
- 2026-11-02
CVE List
An issue was discovered in the ALU unit of the OR1200 (aka OpenRISC 1200) processor 2011-09-10 through 2015-11-11. The overflow flag is not being updated correctly for the subtract instruction, which results in an incorrect value in the overflow flag. Any software that relies on this flag may experience corruption in execution.
- Record
CVE-2021-40507- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-287
- Updated
- 2026-11-02
EUVDEUVD-2021-27683
An issue was discovered in the ALU unit of the OR1200 (aka OpenRISC 1200) processor 2011-09-10 through 2015-11-11. The overflow flag is not being updated correctly for the subtract instruction, which results in an incorrect value in the overflow flag. Any software that relies on this flag may experience corruption in execution.
- Record
EUVD-2021-27683- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-fw2g-jg6j-943h
An issue was discovered in the ALU unit of the OR1200 (aka OpenRISC 1200) processor 2011-09-10...
An issue was discovered in the ALU unit of the OR1200 (aka OpenRISC 1200) processor 2011-09-10 through 2015-11-11. The overflow flag is not being updated correctly for the subtract instruction, which results in an incorrect value in the overflow flag. Any software that relies on this flag may experience corruption in execution.
- Record
GHSA-fw2g-jg6j-943h- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-287
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-40507 is a critical vulnerability (CVSS 9.8) in Openrisc Or1200 Firmware, published April 18, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.73%, the 54th percentile. No source names a fixed version.