Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to heap corruption. An unauthenticated network attacker exploiting this vulnerability could execute arbitrary code.
| Vendor | Product | Versions |
|---|---|---|
| exim | exim | 4.97, 4.99.0, 4.99.1, 4.99.2 |
Downstream vendors/products affected by this vulnerability
| Vendor | Product | Source | Confidence |
|---|---|---|---|
| canonical | ubuntu linux | cert_advisory | 90% |
| debian | debian linux | cert_advisory | 90% |
| open source | exim | cert_advisory | 90% |
Updated affected versions to include 4.99.0, 4.99.1, and 4.99.2, and marked the vulnerability as actively exploited with an exploit available.
Updated description with technical details, added affected version 4.99.2, and marked the exploit as actively exploited.
Updated affected versions to include 4.99.2 and confirmed no exploit is available.
Initial creation
