Debian: Security Advisory (DLA-2556-1)

# 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("1.3.6.1.4.1.25623.1.0.892556");
  script_cve_id("CVE-2020-12662", "CVE-2020-12663", "CVE-2020-28935");
  script_tag(name:"creation_date", value:"2021-02-14 04:00:22 +0000 (Sun, 14 Feb 2021)");
  script_version("2024-02-02T05:06:07+0000");
  script_tag(name:"last_modification", value:"2024-02-02 05:06:07 +0000 (Fri, 02 Feb 2024)");
  script_tag(name:"cvss_base", value:"5.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:P");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2020-05-20 13:42:44 +0000 (Wed, 20 May 2020)");

  script_name("Debian: Security Advisory (DLA-2556-1)");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2021 Greenbone AG");
  script_family("Debian Local Security Checks");
  script_dependencies("gather-package-list.nasl");
  script_mandatory_keys("ssh/login/debian_linux", "ssh/login/packages", re:"ssh/login/release=DEB9");

  script_xref(name:"Advisory-ID", value:"DLA-2556-1");
  script_xref(name:"URL", value:"https://www.debian.org/lts/security/2021/DLA-2556-1");
  script_xref(name:"URL", value:"https://security-tracker.debian.org/tracker/unbound1.9");
  script_xref(name:"URL", value:"https://wiki.debian.org/LTS");

  script_tag(name:"summary", value:"The remote host is missing an update for the Debian 'unbound1.9' package(s) announced via the DLA-2556-1 advisory.");

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

  script_tag(name:"insight", value:"Several security vulnerabilities have been corrected in unbound, a validating, recursive, caching DNS resolver. Support for the unbound DNS server has been resumed, the sources can be found in the unbound1.9 source package.

CVE-2020-12662

Unbound has Insufficient Control of Network Message Volume, aka an NXNSAttack issue. This is triggered by random subdomains in the NSDNAME in NS records.

CVE-2020-12663

Unbound has an infinite loop via malformed DNS answers received from upstream servers.

CVE-2020-28935

Unbound contains a local vulnerability that would allow for a local symlink attack. When writing the PID file Unbound creates the file if it is not there, or opens an existing file for writing. In case the file was already present, it would follow symlinks if the file happened to be a symlink instead of a regular file.

For Debian 9 stretch, these problems have been fixed in version 1.9.0-2+deb10u2~deb9u1.

We recommend that you upgrade your unbound1.9 packages.

For the detailed security status of unbound1.9 please refer to its security tracker page at: [link moved to references]

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: [link moved to references]");

  script_tag(name:"affected", value:"'unbound1.9' package(s) on Debian 9.");

  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-deb.inc");

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

res = "";
report = "";

if(release == "DEB9") {

  if(!isnull(res = isdpkgvuln(pkg:"libunbound8", ver:"1.9.0-2+deb10u2~deb9u1", rls:"DEB9"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"unbound", ver:"1.9.0-2+deb10u2~deb9u1", rls:"DEB9"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"unbound-anchor", ver:"1.9.0-2+deb10u2~deb9u1", rls:"DEB9"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"unbound-host", ver:"1.9.0-2+deb10u2~deb9u1", rls:"DEB9"))) {
    report += res;
  }

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

exit(0);