Mageia: Security Advisory (MGASA-2022-0436)

# SPDX-FileCopyrightText: 2022 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("1.3.6.1.4.1.25623.1.1.10.2022.0436");
  script_cve_id("CVE-2021-36369");
  script_tag(name:"creation_date", value:"2022-11-25 04:11:46 +0000 (Fri, 25 Nov 2022)");
  script_version("2024-02-02T05:06:09+0000");
  script_tag(name:"last_modification", value:"2024-02-02 05:06:09 +0000 (Fri, 02 Feb 2024)");
  script_tag(name:"cvss_base", value:"7.8");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:C/A:N");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2022-10-14 20:03:13 +0000 (Fri, 14 Oct 2022)");

  script_name("Mageia: Security Advisory (MGASA-2022-0436)");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2022 Greenbone AG");
  script_family("Mageia Linux Local Security Checks");
  script_dependencies("gather-package-list.nasl");
  script_mandatory_keys("ssh/login/mageia_linux", "ssh/login/release", re:"ssh/login/release=MAGEIA8");

  script_xref(name:"Advisory-ID", value:"MGASA-2022-0436");
  script_xref(name:"URL", value:"https://advisories.mageia.org/MGASA-2022-0436.html");
  script_xref(name:"URL", value:"https://bugs.mageia.org/show_bug.cgi?id=31119");
  script_xref(name:"URL", value:"https://github.com/mkj/dropbear/pull/128");

  script_tag(name:"summary", value:"The remote host is missing an update for the 'dropbear' package(s) announced via the MGASA-2022-0436 advisory.");

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

  script_tag(name:"insight", value:"Updated dropbear package fixes a security vulnerability in dbclient:.
Due to a non-RFC-compliant check of the available authentication methods
in the client-side SSH code, it is possible for an SSH server to change
the login process in its favor. This attack can bypass additional security
measures such as FIDO2 tokens or SSH-Askpass. Thus, it allows an attacker
to abuse a forwarded agent for logging on to another server unnoticed.

The fix adds a new option, DisableTrivialAuth, to dbclient to disable this
attack vector. Invoke dbclient as
'dbclient -o DisableTrivialAuth=yes localhost ...' to enable this mitigation
on each dbclient invocation.");

  script_tag(name:"affected", value:"'dropbear' package(s) on Mageia 8.");

  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 == "MAGEIA8") {

  if(!isnull(res = isrpmvuln(pkg:"dropbear", rpm:"dropbear~2020.81~1.1.mga8", rls:"MAGEIA8"))) {
    report += res;
  }

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

exit(0);