Moderate: xorg-x11-server security update (Amazon Linux 2)

Package updates are available for Amazon Linux 2 that fix the following vulnerabilities: CVE-2018-15864: Unchecked NULL pointer usage in resolve_keysym in xkbcomp/parser.y in xkbcommon before 0.8.2 could be used by local attackers to crash (NULL pointer dereference) the xkbcommon parser by supplying a crafted keymap file, because a map access attempt can occur for a map that was never created. 1623033: CVE-2018-15864 libxkbcommon: NULL pointer dereference in resolve_keysym resulting in a crash CVE-2018-15863: Unchecked NULL pointer usage in ResolveStateAndPredicate in xkbcomp/compat.c in xkbcommon before 0.8.2 could be used by local attackers to crash (NULL pointer dereference) the xkbcommon parser by supplying a crafted keymap file with a no-op modmask expression. 1623030: CVE-2018-15863 libxkbcommon: NULL pointer dereference in ResolveStateAndPredicate resulting in a crash CVE-2018-15862: Unchecked NULL pointer usage in LookupModMask in xkbcomp/expr.c in xkbcommon before 0.8.2 could be used by local attackers to crash (NULL pointer dereference) the xkbcommon parser by supplying a crafted keymap file with invalid virtual modifiers. 1623029: CVE-2018-15862 libxkbcommon: NULL pointer dereference in LookupModMask resulting in a crash CVE-2018-15861: Unchecked NULL pointer usage in ExprResolveLhs in xkbcomp/expr.c in xkbcommon before 0.8.2 could be used by local attackers to crash (NULL pointer dereference) the xkbcommon parser by supplying a crafted keymap file that triggers an xkb_intern_atom failure. 1623028: CVE-2018-15861 libxkbcommon: NULL pointer dereference in ExprResolveLhs resulting in a crash CVE-2018-15859: Unchecked NULL pointer usage when parsing invalid atoms in ExprResolveLhs in xkbcomp/expr.c in xkbcommon before 0.8.2 could be used by local attackers to crash (NULL pointer dereference) the xkbcommon parser by supplying a crafted keymap file, because lookup failures are mishandled. 1623026: CVE-2018-15859 libxkbcommon: NULL pointer dereference when parsing invalid atoms in ExprResolveLhs resulting in a crash CVE-2018-15857: An invalid free in ExprAppendMultiKeysymList in xkbcomp/ast-build.c in xkbcommon before 0.8.1 could be used by local attackers to crash xkbcommon keymap parsers or possibly have unspecified other impact by supplying a crafted keymap file. 1623022: CVE-2018-15857 libxkbcommon: Invalid free in ExprAppendMultiKeysymList resulting in a crash CVE-2018-15856: An infinite loop when reaching EOL unexpectedly in compose/parser.c (aka the keymap parser) in xkbcommon before 0.8.1 could be used by local attackers to cause a denial of service during parsing of crafted keymap files. 1623018: CVE-2018-15856 libxkbcommon: Infinite loop when reaching EOL unexpectedly resulting in a crash CVE-2018-15855: Unchecked NULL pointer usage in xkbcommon before 0.8.1 could be used by local attackers to crash (NULL pointer dereference) the xkbcommon parser by supplying a crafted keymap file, because the XkbFile for an xkb_geometry section was mishandled. 1623013: CVE-2018-15855 libxkbcommon: NULL pointer dereference when handling xkb_geometry CVE-2018-15854: Unchecked NULL pointer usage in xkbcommon before 0.8.1 could be used by local attackers to crash (NULL pointer dereference) the xkbcommon parser by supplying a crafted keymap file, because geometry tokens were desupported incorrectly. 1623012: CVE-2018-15854 libxkbcommon: NULL pointer dereference resulting in a crash CVE-2018-15853: Endless recursion exists in xkbcomp/expr.c in xkbcommon and libxkbcommon before 0.8.1, which could be used by local attackers to crash xkbcommon users by supplying a crafted keymap file that triggers boolean negation. 1623009: CVE-2018-15853 libxkbcommon: Endless recursion in xkbcomp/expr.c resulting in a crash CVE-2018-14600: An issue was discovered in libX11 through 1.6.5. The function XListExtensions in ListExt.c interprets a variable as signed instead of unsigned, resulting in an out-of-bounds write (of up to 128 bytes), leading to DoS or remote code execution. 1623242: CVE-2018-14600 libX11: Out of Bounds write in XListExtensions in ListExt.c CVE-2018-14599: An off-by-one error has been discovered in libX11 in functions XGetFontPath(), XListExtensions(), and XListFonts(). An attacker who can either configure a malicious X server or modify the data coming from one could use this flaw to make the program crash or have other unspecified effects, caused by the memory corruption. An issue was discovered in libX11 through 1.6.5. The function XListExtensions in ListExt.c is vulnerable to an off-by-one error caused by malicious server responses, leading to DoS or possibly unspecified other impact. 1623250: CVE-2018-14599 libX11: Off-by-one error in XListExtensions in ListExt.c 1623250: CVE-2018-14599 libX11: off-by-one error in XListExtensions in ListExt.c CVE-2018-14598: It was discovered that libX11 does not properly validate input coming from the server, causing XListExtensions() and XGetFontPath() functions to produce an invalid list of elements that in turn make XFreeExtensionsList() and XFreeFontPath() access invalid memory. An attacker who can either configure a malicious X server or modify the data coming from one, could use this flaw to crash the application using libX11, resulting in a denial of service. An issue was discovered in XListExtensions in ListExt.c in libX11 through 1.6.5. A malicious server can send a reply in which the first string overflows, causing a variable to be set to NULL that will be freed later on, leading to DoS (segmentation fault). 1623238: CVE-2018-14598 libX11: Crash on invalid reply in XListExtensions in ListExt.c 1623238: CVE-2018-14598 libX11: Crash on invalid reply in XListExtensions in ListExt.c