LibVNC before commit 502821828ed00b4a2c4bef90683d0fd88ce495de contains a heap out-of-bound write vulnerability in the server code of the file transfer extension, which can result in remote code execution. This attack appears to be exploitable via network connectivity. This vulnerability has been fixed in 502821828ed00b4a2c4bef90683d0fd88ce495de and later. External Reference: https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-028-libvnc-heap-out-of-bound-write/ Upstream Patch: https://github.com/LibVNC/libvncserver/commit/502821828ed00b4a2c4bef90683d0fd88ce495de
Created libvncserver tracking bugs for this issue: Affects: epel-7 [bug 1661104] Affects: fedora-all [bug 1661103]
Upstream Issue: https://github.com/LibVNC/libvncserver/issues/243
Reference: https://seclists.org/oss-sec/2018/q4/212
Final correction was handled in <https://github.com/LibVNC/libvncserver/pull/276>. A complete fix for this issue consists of these three upstream commits: commit 502821828ed00b4a2c4bef90683d0fd88ce495de Author: Christian Beier <dontmind> Date: Sun Oct 21 20:21:30 2018 +0200 LibVNCServer: fix heap out-of-bound write access Closes #243 commit 15bb719c03cc70f14c36a843dcb16ed69b405707 Author: Christian Beier <dontmind> Date: Sun Jan 6 15:13:56 2019 +0100 Error out in rfbProcessFileTransferReadBuffer if length can not be allocated re #273 commit 09e8fc02f59f16e2583b34fe1a270c238bd9ffec Author: Petr Písař <ppisar> Date: Mon Jan 7 10:40:01 2019 +0100 Limit lenght to INT_MAX bytes in rfbProcessFileTransferReadBuffer() This ammends 15bb719c03cc70f14c36a843dcb16ed69b405707 fix for a heap out-of-bound write access in rfbProcessFileTransferReadBuffer() when reading a transfered file content in a server. The former fix did not work on platforms with a 32-bit int type (expected by rfbReadExact()). CVE-2018-15127 <https://github.com/LibVNC/libvncserver/issues/243> <https://github.com/LibVNC/libvncserver/issues/273>
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2019:0059 https://access.redhat.com/errata/RHSA-2019:0059