CVE-2026-7736
Description
A flaw was found in osrg GoBGP. A remote attacker can exploit this vulnerability by executing a manipulation that leads to an integer underflow in the parseRibEntry function. This integer underflow can result in low impacts to the system's confidentiality, integrity, and availability.
Statement
This flaw is rated as Important. A remote unauthenticated attacker whose is able to reach the application consuming the GoBGP library to handle MRT information can trigger the integer underflow vulnerability by sending a maliciously crafted packet to the application. The value resulted from the underflow is further used to try to read information from the memory buffer holding the packet itself resulting in a out-of-bounds read. As the Go language is considered memory safe, in this implementation the attacker won't be able to read any unintended data as the Go runtime will case the application to panic meaning there's no integrity or confidentiality impact as consequence of a successful attacker. However when this flaw is exploited, due to the same runtime protection leading the application to panic, a denial-of-service (DoS) is achieved for all users trying to access the application, result in a high impact to the availability aspect.
Mitigation
To mitigate this issue, restrict network access to systems running GoBGP to only trusted BGP peers. Configure firewall rules to limit inbound connections to the BGP port (TCP 179) from known and authorized sources. This will reduce the attack surface by preventing arbitrary remote attackers from sending malicious BGP messages. Any changes to firewall rules or network configurations may require a service reload or restart to take effect, which could temporarily disrupt network services.
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Instability
This weakness will generally lead to undefined behavior and therefore crashes. In the case of overflows involving loop index variables, the likelihood of infinite loops is also high.
Integrity
Technical Impact: Modify Memory
If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the wrap around results in other conditions such as buffer overflows, further memory corruption may occur.
Confidentiality,Availability,Access Control
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism
This weakness can sometimes trigger buffer overflows which can be used to execute arbitrary code. This is usually outside the scope of a program's implicit security policy.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
