Debian: Security Advisory (DLA-1015-1)

# SPDX-FileCopyrightText: 2018 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("1.3.6.1.4.1.25623.1.0.891015");
  script_cve_id("CVE-2017-7526");
  script_tag(name:"creation_date", value:"2018-02-04 23:00:00 +0000 (Sun, 04 Feb 2018)");
  script_version("2024-02-02T05:06:06+0000");
  script_tag(name:"last_modification", value:"2024-02-02 05:06:06 +0000 (Fri, 02 Feb 2024)");
  script_tag(name:"cvss_base", value:"4.3");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:M/Au:N/C:P/I:N/A:N");
  script_tag(name:"severity_vector", value:"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2018-10-02 14:02:49 +0000 (Tue, 02 Oct 2018)");

  script_name("Debian: Security Advisory (DLA-1015-1)");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2018 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=DEB7");

  script_xref(name:"Advisory-ID", value:"DLA-1015-1");
  script_xref(name:"URL", value:"https://www.debian.org/lts/security/2017/DLA-1015-1");

  script_tag(name:"summary", value:"The remote host is missing an update for the Debian 'libgcrypt11' package(s) announced via the DLA-1015-1 advisory.");

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

  script_tag(name:"insight", value:"It was discovered that there was a key disclosure vulnerability in libgcrypt11 a library of cryptographic routines:

It is well known that constant-time implementations of modular exponentiation cannot use sliding windows. However, software libraries such as Libgcrypt, used by GnuPG, continue to use sliding windows. It is widely believed that, even if the complete pattern of squarings and multiplications is observed through a side-channel attack, the number of exponent bits leaked is not sufficient to carry out a full key-recovery attack against RSA. Specifically, 4-bit sliding windows leak only 40% of the bits, and 5-bit sliding windows leak only 33% of the bits.

-- Sliding right into disaster: Left-to-right sliding windows leak

For Debian 7 Wheezy, this issue has been fixed in libgcrypt11 version 1.5.0-5+deb7u6.

We recommend that you upgrade your libgcrypt11 packages.");

  script_tag(name:"affected", value:"'libgcrypt11' package(s) on Debian 7.");

  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 == "DEB7") {

  if(!isnull(res = isdpkgvuln(pkg:"libgcrypt11", ver:"1.5.0-5+deb7u6", rls:"DEB7"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"libgcrypt11-dbg", ver:"1.5.0-5+deb7u6", rls:"DEB7"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"libgcrypt11-dev", ver:"1.5.0-5+deb7u6", rls:"DEB7"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"libgcrypt11-doc", ver:"1.5.0-5+deb7u6", rls:"DEB7"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"libgcrypt11-udeb", ver:"1.5.0-5+deb7u6", rls:"DEB7"))) {
    report += res;
  }

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

exit(0);