BIG-IP: Incorrect Calculation
CVE-2022-26517 is a high-severity incorrect calculation vulnerability in BIG-IP from F5, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 15.1.5.1, 14.1.4.6, 13.1.5 as the first without the flaw, so updating BIG-IP to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.82% chance of exploitation within 30 days, higher than 58% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update BIG-IP to 15.1.5.1 or 14.1.4.6 or 13.1.5, whichever matches your release line, or a later version.
- Read the advisory on support.f5.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 |
|---|---|---|---|
| F5 | BIG-IP | 15.1.x up to, but not including, 15.1.5.1; 14.1.x up to, but not including, 14.1.4.6; 13.1.x up to, but not including, 13.1.5 | 15.1.5.1, 14.1.4.6, 13.1.5 |
| F5 | Big-ip Access Policy Manager | 13.1.0; 13.1.1; 13.1.3; 13.1.4; 13.1.5; 14.1.0; 14.1.2; 14.1.3; and 10 more ranges | Not stated |
| F5 | Big-ip Advanced Firewall Manager | 13.1.0; 13.1.1; 13.1.3; 13.1.4; 13.1.5; 14.1.0; 14.1.2; 14.1.3; and 10 more ranges | Not stated |
| F5 | Big-ip Analytics | 13.1.0; 13.1.1; 13.1.3; 13.1.4; 13.1.5; 14.1.0; 14.1.2; 14.1.3; and 10 more ranges | Not stated |
| F5 | Big-ip Application Acceleration Manager | 13.1.0; 13.1.1; 13.1.3; 13.1.4; 13.1.5; 14.1.0; 14.1.2; 14.1.3; and 10 more ranges | Not stated |
| F5 | Big-ip Application Security Manager | 13.1.0; 13.1.1; 13.1.3; 13.1.4; 13.1.5; 14.1.0; 14.1.2; 14.1.3; and 10 more ranges | Not stated |
| F5 | Big-ip Domain Name System | 13.1.0; 13.1.1; 13.1.3; 13.1.4; 13.1.5; 14.1.0; 14.1.2; 14.1.3; and 10 more ranges | Not stated |
| F5 | Big-ip Fraud Protection Service | 13.1.0; 13.1.1; 13.1.3; 13.1.4; 13.1.5; 14.1.0; 14.1.2; 14.1.3; and 10 more ranges | Not stated |
| F5 | Big-ip Global Traffic Manager | 13.1.0; 13.1.1; 13.1.3; 13.1.4; 13.1.5; 14.1.0; 14.1.2; 14.1.3; and 10 more ranges | Not stated |
| F5 | Big-ip Link Controller | 13.1.0; 13.1.1; 13.1.3; 13.1.4; 13.1.5; 14.1.0; 14.1.2; 14.1.3; and 10 more ranges | Not stated |
| F5 | Big-ip Local Traffic Manager | 13.1.0; 13.1.1; 13.1.3; 13.1.4; 13.1.5; 14.1.0; 14.1.2; 14.1.3; and 10 more ranges | Not stated |
| F5 | Big-ip Policy Enforcement Manager | 13.1.0; 13.1.1; 13.1.3; 13.1.4; 13.1.5; 14.1.0; 14.1.2; 14.1.3; and 10 more ranges | 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
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 5.9 | Medium | CNA (f5.com) |
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 2.0 | 5.0 | Medium | NVD |
Official description
On F5 BIG-IP 15.1.x versions prior to 15.1.5.1, 14.1.x versions prior to 14.1.4.6, and 13.1.x versions prior to 13.1.5, when the BIG-IP CGNAT Large Scale NAT (LSN) pool is configured on a virtual server and packet filtering is enabled, undisclosed requests can cause the Traffic Management Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Calculation
The product performs a calculation that generates incorrect or unintended results that are later used in security-critical decisions or resource management.
How developers prevent this class of flaw
- Understand your programming language's underlying representation and how it interacts with numeric calculation. Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, not-a-number calculations, and how your language handles numbers that are too large or too small for its underlying 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.
- Use the appropriate type for the desired action. For example, in C/C++, only use unsigned types for values that could never be negative, such as height, width, or other numbers related to quantity.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in BIG-IP
- 9.8 Critical severity
F5 BIG-IP APM Heap-based Buffer Overflow Exploited
- 8.8 High severity
- 7.5 High severity
- 8.7 High severity
- 8.7 High severity
- 7.5 High severity
Recent Incorrect Calculation vulnerabilities
- 7.5 High severity
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