Huawei EulerOS: Security Advisory for libssh (EulerOS-SA-2021-2787)

# 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("1.3.6.1.4.1.25623.1.1.2.2021.2787");
  script_cve_id("CVE-2021-3634");
  script_tag(name:"creation_date", value:"2021-11-17 03:46:51 +0000 (Wed, 17 Nov 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:"4.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:S/C:N/I:N/A:P");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2021-09-09 01:02:09 +0000 (Thu, 09 Sep 2021)");

  script_name("Huawei EulerOS: Security Advisory for libssh (EulerOS-SA-2021-2787)");
  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=EULEROSVIRT\-2\.9\.0");

  script_xref(name:"Advisory-ID", value:"EulerOS-SA-2021-2787");
  script_xref(name:"URL", value:"https://developer.huaweicloud.com/intl/en-us/euleros/securitydetail.html?secId=EulerOS-SA-2021-2787");

  script_tag(name:"summary", value:"The remote host is missing an update for the Huawei EulerOS 'libssh' package(s) announced via the EulerOS-SA-2021-2787 advisory.");

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

  script_tag(name:"insight", value:"A flaw has been found in libssh in versions prior to 0.9.6. The SSH protocol keeps track of two shared secrets during the lifetime of the session. One of them is called secret_hash and the other session_id. Initially, both of them are the same, but after key re-exchange, previous session_id is kept and used as an input to new secret_hash. Historically, both of these buffers had shared length variable, which worked as long as these buffers were same. But the key re-exchange operation can also change the key exchange method, which can be based on hash of different size, eventually creating 'secret_hash' of different size than the session_id has. This becomes an issue when the session_id memory is zeroed or when it is used again during second key re-exchange.(CVE-2021-3634)");

  script_tag(name:"affected", value:"'libssh' package(s) on Huawei EulerOS Virtualization release 2.9.0.");

  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 == "EULEROSVIRT-2.9.0") {

  if(!isnull(res = isrpmvuln(pkg:"libssh", rpm:"libssh~0.9.4~1.h3.eulerosv2r9", rls:"EULEROSVIRT-2.9.0"))) {
    report += res;
  }

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

exit(0);