An important fact that I only recently learned about this vulnerability is that the change that introduced it was not some rushed act: the maintainer raised the problem they were seeing on the OpenSSL mailing list, proposed a change to fix the problem with a request for feedback, and got some (including from upstream).
The result was a terrible vulnerability, but it seems more of a case of spectacularly bad luck of everyone not spotting the issue.
The result was a terrible vulnerability, but it seems more of a case of spectacularly bad luck of everyone not spotting the issue.