Huawei EulerOS: Security Advisory for libvncserver (EulerOS-SA-2021-1321)

# SPDX-FileCopyrightText: 2021 Greenbone AG
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-only

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.1.2.2021.1321");
  script_cve_id("CVE-2016-9942", "CVE-2017-18922", "CVE-2019-15681", "CVE-2020-25708");
  script_tag(name:"creation_date", value:"2021-02-22 08:38:27 +0000 (Mon, 22 Feb 2021)");
  script_version("2024-02-05T14:36:56+0000");
  script_tag(name:"last_modification", value:"2024-02-05 14:36:56 +0000 (Mon, 05 Feb 2024)");
  script_tag(name:"cvss_base", value:"7.5");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2020-07-06 19:14:21 +0000 (Mon, 06 Jul 2020)");

  script_name("Huawei EulerOS: Security Advisory for libvncserver (EulerOS-SA-2021-1321)");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2021 Greenbone AG");
  script_family("Huawei EulerOS Local Security Checks");
  script_dependencies("gb_huawei_euleros_consolidation.nasl");
  script_mandatory_keys("ssh/login/euleros", "ssh/login/rpms", re:"ssh/login/release=EULEROS\-2\.0SP2");

  script_xref(name:"Advisory-ID", value:"EulerOS-SA-2021-1321");
  script_xref(name:"URL", value:"https://developer.huaweicloud.com/intl/en-us/euleros/securitydetail.html?secId=EulerOS-SA-2021-1321");

  script_tag(name:"summary", value:"The remote host is missing an update for the Huawei EulerOS 'libvncserver' package(s) announced via the EulerOS-SA-2021-1321 advisory.");

  script_tag(name:"vuldetect", value:"Checks if a vulnerable package version is present on the target host.");

  script_tag(name:"insight", value:"Heap-based buffer overflow in ultra.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted FramebufferUpdate message with the Ultra type tile, such that the LZO payload decompressed length exceeds what is specified by the tile dimensions.(CVE-2016-9942)

It was discovered that websockets.c in LibVNCServer prior to 0.9.12 did not properly decode certain WebSocket frames. A malicious attacker could exploit this by sending specially crafted WebSocket frames to a server, causing a heap-based buffer overflow.(CVE-2017-18922)

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.(CVE-2019-15681)

A divide by zero issue was found to occur in libvncserver-0.9.12. A malicious client could use this flaw to send a specially crafted message that, when processed by the VNC server, would lead to a floating point exception, resulting in a denial of service.(CVE-2020-25708)");

  script_tag(name:"affected", value:"'libvncserver' package(s) on Huawei EulerOS V2.0SP2.");

  script_tag(name:"solution", value:"Please install the updated package(s).");

  script_tag(name:"solution_type", value:"VendorFix");
  script_tag(name:"qod_type", value:"package");

  exit(0);
}

include("revisions-lib.inc");
include("pkg-lib-rpm.inc");

release = rpm_get_ssh_release();
if(!release)
  exit(0);

res = "";
report = "";

if(release == "EULEROS-2.0SP2") {

  if(!isnull(res = isrpmvuln(pkg:"libvncserver", rpm:"libvncserver~0.9.9~12.h8", rls:"EULEROS-2.0SP2"))) {
    report += res;
  }

  if(report != "") {
    security_message(data:report);
  } else if(__pkg_match) {
    exit(99);
  }
  exit(0);
}

exit(0);