OpenBSD 5.3 errata 15, Apr 12, 2014: A use-after-free race condition in OpenSSL's read buffer may permit an attacker to inject data from one connection into another. The advice in the previous OpenSSL errata also applies. Apply patch using: cat 015_openssl.patch | (cd /usr/src && patch -p0) Then build and install libssl cd /usr/src/lib/libssl/ssl make obj make make install Also recompile any statically-linked binaries depending on it - in the base OS, this is just ftp(1): cd /usr/src/usr.bin/ftp make obj make clean make make install Then restart services which depend on SSL. Index: lib/libssl/src/ssl/s3_pkt.c =================================================================== RCS file: /cvs/src/lib/libssl/src/ssl/s3_pkt.c,v retrieving revision 1.19 retrieving revision 1.19.2.1 diff -u -p -u -r1.19 -r1.19.2.1 --- lib/libssl/src/ssl/s3_pkt.c 14 Feb 2013 15:11:43 -0000 1.19 +++ lib/libssl/src/ssl/s3_pkt.c 12 Apr 2014 17:00:22 -0000 1.19.2.1 @@ -1054,7 +1054,7 @@ start: { s->rstate=SSL_ST_READ_HEADER; rr->off=0; - if (s->mode & SSL_MODE_RELEASE_BUFFERS) + if (s->mode & SSL_MODE_RELEASE_BUFFERS && s->s3->rbuf.left == 0) ssl3_release_read_buffer(s); } }