Vulnerabilities > CVE-2017-15994 - Improper Validation of Integrity Check Value vulnerability in Samba Rsync

047910
CVSS 9.8 - CRITICAL
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
HIGH
network
low complexity
samba
CWE-354
critical
nessus
NVD
Published: 2017-10-29
Updated: 2023-11-07

Summary

rsync 3.1.3-development before 2017-10-24 mishandles archaic checksums, which makes it easier for remote attackers to bypass intended access restrictions. NOTE: the rsync development branch has significant use beyond the rsync developers, e.g., the code has been copied for use in various GitHub projects.

Vulnerable Configurations

Part Description Count
Application
Samba
170

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Padding Oracle Crypto Attack
    An attacker is able to efficiently decrypt data without knowing the decryption key if a target system leaks data on whether or not a padding error happened while decrypting the ciphertext. A target system that leaks this type of information becomes the padding oracle and an attacker is able to make use of that oracle to efficiently decrypt data without knowing the decryption key by issuing on average 128*b calls to the padding oracle (where b is the number of bytes in the ciphertext block). In addition to performing decryption, an attacker is also able to produce valid ciphertexts (i.e., perform encryption) by using the padding oracle, all without knowing the encryption key. Any cryptosystem can be vulnerable to padding oracle attacks if the encrypted messages are not authenticated to ensure their validity prior to decryption, and then the information about padding error is leaked to the attacker. This attack technique may be used, for instance, to break CAPTCHA systems or decrypt/modify state information stored in client side objects (e.g., hidden fields or cookies). This attack technique is a side-channel attack on the cryptosystem that uses a data leak from an improperly implemented decryption routine to completely subvert the cryptosystem. The one bit of information that tells the attacker whether a padding error during decryption has occurred, in whatever form it comes, is sufficient for the attacker to break the cryptosystem. That bit of information can come in a form of an explicit error message about a padding error, a returned blank page, or even the server taking longer to respond (a timing attack). This attack can be launched cross domain where an attacker is able to use cross-domain information leaks to get the bits of information from the padding oracle from a target system / service with which the victim is communicating. To do so an attacker sends a request containing ciphertext to the target system. Due to the browser's same origin policy, the attacker is not able to see the response directly, but can use cross-domain information leak techniques to still get the information needed (i.e., information on whether or not a padding error has occurred). For instance, this can be done using "img" tag plus the onerror()/onload() events. The attacker's JavaScript can make web browsers to load an image on the target site, and know if the image is loaded or not. This is 1-bit information needed for the padding oracle attack to work: if the image is loaded, then it is valid padding, otherwise it is not.
  • Manipulating Writeable Configuration Files
    Generally these are manually edited files that are not in the preview of the system administrators, any ability on the attackers' behalf to modify these files, for example in a CVS repository, gives unauthorized access directly to the application, the same as authorized users.

Nessus

  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2020-1257.NASL
    descriptionAccording to the versions of the rsync package installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerabilities : - The recv_files function in receiver.c in the daemon in rsync 3.1.2, and 3.1.3-development before 2017-12-03, proceeds with certain file metadata updates before checking for a filename in the daemon_filter_list data structure, which allows remote attackers to bypass intended access restrictions.(CVE-2017-17433) - rsync 3.1.3-development before 2017-10-24 mishandles archaic checksums, which makes it easier for remote attackers to bypass intended access restrictions. NOTE: the rsync development branch has significant use beyond the rsync developers, e.g., the code has been copied for use in various GitHub projects.(CVE-2017-15994) Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-03-19
    modified2020-03-13
    plugin id134546
    published2020-03-13
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/134546
    titleEulerOS Virtualization for ARM 64 3.0.2.0 : rsync (EulerOS-SA-2020-1257)
    code
    #
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(134546);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/03/19");

  script_cve_id(
    "CVE-2017-15994",
    "CVE-2017-17433"
  );

  script_name(english:"EulerOS Virtualization for ARM 64 3.0.2.0 : rsync (EulerOS-SA-2020-1257)");
  script_summary(english:"Checks the rpm output for the updated packages.");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS Virtualization for ARM 64 host is missing multiple security
updates.");
  script_set_attribute(attribute:"description", value:
"According to the versions of the rsync package installed, the EulerOS
Virtualization for ARM 64 installation on the remote host is affected
by the following vulnerabilities :

  - The recv_files function in receiver.c in the daemon in
    rsync 3.1.2, and 3.1.3-development before 2017-12-03,
    proceeds with certain file metadata updates before
    checking for a filename in the daemon_filter_list data
    structure, which allows remote attackers to bypass
    intended access restrictions.(CVE-2017-17433)

  - rsync 3.1.3-development before 2017-10-24 mishandles
    archaic checksums, which makes it easier for remote
    attackers to bypass intended access restrictions. NOTE:
    the rsync development branch has significant use beyond
    the rsync developers, e.g., the code has been copied
    for use in various GitHub projects.(CVE-2017-15994)

Note that Tenable Network Security has extracted the preceding
description block directly from the EulerOS security advisory. Tenable
has attempted to automatically clean and format it as much as possible
without introducing additional issues.");
  # https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2020-1257
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?7d7c91e6");
  script_set_attribute(attribute:"solution", value:
"Update the affected rsync packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"patch_publication_date", value:"2020/03/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/03/13");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:rsync");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:uvp:3.0.2.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Huawei Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/cpu", "Host/EulerOS/release", "Host/EulerOS/rpm-list", "Host/EulerOS/uvp_version");

  exit(0);
}

include("audit.inc");
include("global_settings.inc");
include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

release = get_kb_item("Host/EulerOS/release");
if (isnull(release) || release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
uvp = get_kb_item("Host/EulerOS/uvp_version");
if (uvp != "3.0.2.0") audit(AUDIT_OS_NOT, "EulerOS Virtualization 3.0.2.0");
if (!get_kb_item("Host/EulerOS/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("aarch64" >!< cpu) audit(AUDIT_ARCH_NOT, "aarch64", cpu);

flag = 0;

pkgs = ["rsync-3.1.2-4.h4"];

foreach (pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", reference:pkg)) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "rsync");
}
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2020-1497.NASL
    descriptionAccording to the versions of the rsync package installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities : - The receive_xattr function in xattrs.c in rsync 3.1.2 and 3.1.3-development does not check for a trailing
    last seen2020-04-30
    modified2020-04-16
    plugin id135659
    published2020-04-16
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/135659
    titleEulerOS Virtualization 3.0.2.2 : rsync (EulerOS-SA-2020-1497)
    code
    #
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(135659);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/04/24");

  script_cve_id(
    "CVE-2017-15994",
    "CVE-2017-16548",
    "CVE-2017-17433",
    "CVE-2018-5764"
  );

  script_name(english:"EulerOS Virtualization 3.0.2.2 : rsync (EulerOS-SA-2020-1497)");
  script_summary(english:"Checks the rpm output for the updated packages.");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS Virtualization host is missing multiple security
updates.");
  script_set_attribute(attribute:"description", value:
"According to the versions of the rsync package installed, the EulerOS
Virtualization installation on the remote host is affected by the
following vulnerabilities :

  - The receive_xattr function in xattrs.c in rsync 3.1.2
    and 3.1.3-development does not check for a trailing
    '\0' character in an xattr name, which allows remote
    attackers to cause a denial of service (heap-based
    buffer over-read and application crash) or possibly
    have unspecified other impact by sending crafted data
    to the daemon.(CVE-2017-16548)

  - The parse_arguments function in options.c in rsyncd in
    rsync before 3.1.3 does not prevent multiple
    --protect-args uses, which allows remote attackers to
    bypass an argument-sanitization protection
    mechanism.(CVE-2018-5764)

  - The recv_files function in receiver.c in the daemon in
    rsync 3.1.2, and 3.1.3-development before 2017-12-03,
    proceeds with certain file metadata updates before
    checking for a filename in the daemon_filter_list data
    structure, which allows remote attackers to bypass
    intended access restrictions.(CVE-2017-17433)

  - rsync 3.1.3-development before 2017-10-24 mishandles
    archaic checksums, which makes it easier for remote
    attackers to bypass intended access restrictions. NOTE:
    the rsync development branch has significant use beyond
    the rsync developers, e.g., the code has been copied
    for use in various GitHub projects.(CVE-2017-15994)

Note that Tenable Network Security has extracted the preceding
description block directly from the EulerOS security advisory. Tenable
has attempted to automatically clean and format it as much as possible
without introducing additional issues.");
  # https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2020-1497
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?08938f68");
  script_set_attribute(attribute:"solution", value:
"Update the affected rsync packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"patch_publication_date", value:"2020/04/16");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/04/16");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:rsync");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:uvp:3.0.2.2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Huawei Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/cpu", "Host/EulerOS/release", "Host/EulerOS/rpm-list", "Host/EulerOS/uvp_version");

  exit(0);
}

include("audit.inc");
include("global_settings.inc");
include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

release = get_kb_item("Host/EulerOS/release");
if (isnull(release) || release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
uvp = get_kb_item("Host/EulerOS/uvp_version");
if (uvp != "3.0.2.2") audit(AUDIT_OS_NOT, "EulerOS Virtualization 3.0.2.2");
if (!get_kb_item("Host/EulerOS/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_ARCH_NOT, "i686 / x86_64", cpu);

flag = 0;

pkgs = ["rsync-3.1.2-4.h4.eulerosv2r7"];

foreach (pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", reference:pkg)) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "rsync");
}
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2019-1989.NASL
    descriptionAccording to the versions of the rsync package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities : - rsync 3.1.3-development before 2017-10-24 mishandles archaic checksums, which makes it easier for remote attackers to bypass intended access restrictions. NOTE: the rsync development branch has significant use beyond the rsync developers, e.g., the code has been copied for use in various GitHub projects.(CVE-2017-15994) - The recv_files function in receiver.c in the daemon in rsync 3.1.2, and 3.1.3-development before 2017-12-03, proceeds with certain file metadata updates before checking for a filename in the daemon_filter_list data structure, which allows remote attackers to bypass intended access restrictions.(CVE-2017-17433) Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-05-08
    modified2019-09-24
    plugin id129183
    published2019-09-24
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/129183
    titleEulerOS 2.0 SP5 : rsync (EulerOS-SA-2019-1989)

References