An issue was discovered in LibVNCServer before 0.9.13. libvncserver/hextile.c allows out-of-bounds access via encodings.

An issue was discovered in LibVNCServer before 0.9.13. An improperly closed TCP connection causes an infinite loop in libvncclient/sockets.c.

An issue was discovered in LibVNCServer before 0.9.13. Byte-aligned data is accessed through uint16_t pointers in libvncserver/translate.c. NOTE: Third parties do not consider this to be a vulnerability as there is no known path of exploitation or cross of a trust boundary

An issue was discovered in LibVNCServer before 0.9.13. libvncserver/scale.c has a pixel_value integer overflow.

An issue was discovered in LibVNCServer before 0.9.13. libvncserver/ws_decode.c can lead to a crash because of unaligned accesses in hybiReadAndDecode.

An issue was discovered in LibVNCServer before 0.9.13. libvncserver/rre.c allows out-of-bounds access via encodings.

An issue was discovered in LibVNCServer before 0.9.13. libvncclient/rfbproto.c does not limit TextChat size.

libvncclient/cursor.c in LibVNCServer through 0.9.12 has a HandleCursorShape integer overflow and heap-based buffer overflow via a large height or width value. NOTE: this may overlap CVE-2019-15690.

A NULL pointer dereference flaw was found in the way LibVNCServer before 0.9.9 handled certain ClientCutText message. A remote attacker could use this flaw to crash the VNC server by sending a specially crafted ClientCutText message from a VNC client.

LibVNC commit before d01e1bb4246323ba6fcee3b82ef1faa9b1dac82a contains a memory leak (CWE-655) in VNC server code, which allow an attacker to read stack memory and can be abused for information disclosure. Combined with another vulnerability, it can be used to leak stack memory and bypass ASLR. This attack appear to be exploitable via network connectivity. These vulnerabilities have been fixed in commit d01e1bb4246323ba6fcee3b82ef1faa9b1dac82a.