Issue summary: Some non-default TLS server configurations can cause unbounded memory growth when processing TLSv1.3 sessions
Impact summary: An attacker may exploit certain server configurations to trigger unbounded memory growth that would lead to a Denial of Service
This problem can occur in TLSv1.3 if the non-default SSL_OP_NO_TICKET option is being used (but not if early_data support is also configured and the default anti-replay protection is in use). In this case, under certain conditions, the session cache can get into an incorrect state and it will fail to flush properly as it fills. The session cache will continue to grow in an unbounded manner. A malicious client could deliberately create the scenario for this failure to force a Denial of Service. It may also happen by accident in normal operation.
This issue only affects TLS servers supporting TLSv1.3. It does not affect TLS clients.
The FIPS modules in 3.2, 3.1 and 3.0 are not affected by this issue. OpenSSL 1.0.2 is also not affected by this issue.
The product manages a group of objects or resources and performs a separate memory allocation for each object, but it does not properly limit the total amount of memory that is consumed by all of the combined objects.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Red Hat Enterprise Linux 9 | RedHat | openssl-1:3.2.2-6.el9_5 | * |
| Red Hat Enterprise Linux 9 | RedHat | openssl-1:3.2.2-6.el9_5 | * |
| Edk2 | Ubuntu | devel | * |
| Edk2 | Ubuntu | focal | * |
| Edk2 | Ubuntu | jammy | * |
| Edk2 | Ubuntu | mantic | * |
| Edk2 | Ubuntu | noble | * |
| Edk2 | Ubuntu | oracular | * |
| Nodejs | Ubuntu | jammy | * |
| Openssl | Ubuntu | devel | * |
| Openssl | Ubuntu | fips-preview/jammy | * |
| Openssl | Ubuntu | fips-updates/focal | * |
| Openssl | Ubuntu | fips-updates/jammy | * |
| Openssl | Ubuntu | fips/focal | * |
| Openssl | Ubuntu | focal | * |
| Openssl | Ubuntu | jammy | * |
| Openssl | Ubuntu | mantic | * |
| Openssl | Ubuntu | noble | * |
| Openssl | Ubuntu | oracular | * |
While the product might limit the amount of memory that is allocated in a single operation for a single object (such as a malloc of an array), if an attacker can cause multiple objects to be allocated in separate operations, then this might cause higher total memory consumption than the developer intended, leading to a denial of service.