Debian: Security Advisory (DLA-2433-1)

# SPDX-FileCopyrightText: 2020 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("1.3.6.1.4.1.25623.1.0.892433");
  script_cve_id("CVE-2020-26939");
  script_tag(name:"creation_date", value:"2020-11-06 04:00:09 +0000 (Fri, 06 Nov 2020)");
  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:P/I:N/A:N");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2020-11-17 19:32:51 +0000 (Tue, 17 Nov 2020)");

  script_name("Debian: Security Advisory (DLA-2433-1)");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2020 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-2433-1");
  script_xref(name:"URL", value:"https://www.debian.org/lts/security/2020/DLA-2433-1");
  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 'bouncycastle' package(s) announced via the DLA-2433-1 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 an issue in the bouncycastle crypto library where attackers could obtain sensitive information due to observable differences in its response to invalid input.

CVE-2020-26939

In Legion of the Bouncy Castle BC before 1.55 and BC-FJA before 1.0.1.2, attackers can obtain sensitive information about a private exponent because of Observable Differences in Behavior to Error Inputs. This occurs in org.bouncycastle.crypto.encodings.OAEPEncoding. Sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder could result in the throwing of an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.

For Debian 9 Stretch, these problems have been fixed in version 1.56-1+deb9u3.

We recommend that you upgrade your bouncycastle packages.

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:"'bouncycastle' 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:"libbcmail-java", ver:"1.56-1+deb9u3", rls:"DEB9"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"libbcmail-java-doc", ver:"1.56-1+deb9u3", rls:"DEB9"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"libbcpg-java", ver:"1.56-1+deb9u3", rls:"DEB9"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"libbcpg-java-doc", ver:"1.56-1+deb9u3", rls:"DEB9"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"libbcpkix-java", ver:"1.56-1+deb9u3", rls:"DEB9"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"libbcpkix-java-doc", ver:"1.56-1+deb9u3", rls:"DEB9"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"libbcprov-java", ver:"1.56-1+deb9u3", rls:"DEB9"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"libbcprov-java-doc", ver:"1.56-1+deb9u3", rls:"DEB9"))) {
    report += res;
  }

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

exit(0);