Undefined behavior may result due to a race condition leading to a use-after-free violation. If BIND receives an incoming DNS message signed with SIG(0), it begins work to validate that signature. If, during that validation, the "recursive-clients" limit is reached (as would occur during a query flood), and that same DNS message is discarded per the limit, there is a brief window of time while the SIG(0) validation may attempt to read the now-discarded DNS message. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.28 through 9.18.49 and 9.18.28-S1 through 9.18.49-S1 are NOT affected.
| Vendor | Product | Versions |
|---|---|---|
| isc | bind | 9.20.0, 9.21.0, 9.20.9-S1 |
Downstream vendors/products affected by this vulnerability
| Vendor | Product | Source | Confidence |
|---|---|---|---|
| internet systems consortium | bind | cert_advisory | 90% |
Updated exploit availability to true, set patch available to null, and added new CVE tags.
Updated affected versions to include 9.18.48 and 9.18.49-S0, changed severity to MEDIUM, marked as actively exploited, and noted no exploit available.
Initial creation
