Description
stunnel before 5.00, when using fork threading, does not properly update the state of the OpenSSL pseudo-random number generator (PRNG), which causes subsequent children with the same process ID to use the same entropy pool and allows remote attackers to obtain private keys for EC (ECDSA) or DSA certificates.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | stunnel | 5.38-1.1 | openSUSE-SU-2024:10289-1 |
Advisories 1
- openSUSE-SU-2024:10289-1 stunnel-5.38-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026