Description
In the OpenSSL compatibility layer implementation, the function RAND_poll() was not behaving as expected and leading to the potential for predictable values returned from RAND_bytes() after fork() is called. This can lead to weak or predictable random numbers generated in applications that are both using RAND_bytes() and doing fork() operations. This only affects applications explicitly calling RAND_bytes() after fork() and does not affect any internal TLS operations. Although RAND_bytes() documentation in OpenSSL calls out not being safe for use with fork() without first calling RAND_poll(), an additional code change was also made in wolfSSL to make RAND_bytes() behave similar to OpenSSL after a fork() call without calling RAND_poll(). Now the Hash-DRBG used gets reseeded after detecting running in a new process. If making use of RAND_bytes() and calling fork() we recommend updating to the latest version of wolfSSL. Thanks to Per Allansson from Appgate for the report.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| wolfSSL | wolfSSL | — | — |
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.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 13 | wolfssl | 5.7.2-0.1+deb13u1 | — |
| Debian 12 | wolfssl | 5.5.4-2+deb12u2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | wolfssl | No fix yet | — |
| Ubuntu 26.04 LTS | wolfssl | No fix yet | — |
| Ubuntu 25.10 | wolfssl | No fix yet | — |
| Ubuntu 24.04 LTS | wolfssl | No fix yet | — |
| Ubuntu 22.04 LTS | wolfssl | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | wolfssl | No fix yet | — |
| Ubuntu 18.04 LTS | wolfssl | No fix yet | — |
| Ubuntu 16.04 LTS | wolfssl | No fix yet | — |