An issue was discovered in FreeRDP before 2.1.1. An out-of-bounds (OOB) read vulnerability has been detected in ntlm_read_ChallengeMessage in winpr/libwinpr/sspi/NTLM/ntlm_message.c. Upstream Commits: https://github.com/FreeRDP/FreeRDP/commit/48361c411e50826cb602c7aab773a8a20e1da6bc https://github.com/FreeRDP/FreeRDP/commit/8fb6336a4072abcee8ce5bd6ae91104628c7bb69
Created freerdp tracking bugs for this issue: Affects: epel-all [bug 1841190] Created freerdp1.2 tracking bugs for this issue: Affects: fedora-all [bug 1841191]
The patch adds length checking by computing the StartOffset and PayloadOffset with Stream_GetPosition(s) instead of Stream_Pointer(s), then computing the length of the buffer to allocate from those. Also, a NULL check was added prior to copying from stream into buffer. Lastly, The offset and length variables were changed to size_t types. From this info, it looks like that stream pointer could have been pointing to a position which caused an out-of-bounds read of the buffer from within ntlm_read_ChallengeMessage prior to this patch.
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2020:4031 https://access.redhat.com/errata/RHSA-2020:4031
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2020-13396
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2020:4647 https://access.redhat.com/errata/RHSA-2020:4647