Juniper Junos OS Multiple Vulnerabilities (JSA69715)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(166767);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/06");

  script_cve_id(
    "CVE-2020-1968",
    "CVE-2020-1971",
    "CVE-2021-3712",
    "CVE-2021-23839",
    "CVE-2021-23840",
    "CVE-2021-23841"
  );
  script_xref(name:"JSA", value:"JSA69715");
  script_xref(name:"CEA-ID", value:"CEA-2021-0004");
  script_xref(name:"CEA-ID", value:"CEA-2021-0025");

  script_name(english:"Juniper Junos OS Multiple Vulnerabilities (JSA69715)");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch.");
  script_set_attribute(attribute:"description", value:
"The version of Junos OS installed on the remote host is affected by multiple vulnerabilities as referenced in the
JSA69715 advisory.

  - The Raccoon attack exploits a flaw in the TLS specification which can lead to an attacker being able to
    compute the pre-master secret in connections which have used a Diffie-Hellman (DH) based ciphersuite. In
    such a case this would result in the attacker being able to eavesdrop on all encrypted communications sent
    over that TLS connection. The attack can only be exploited if an implementation re-uses a DH secret across
    multiple TLS connections. Note that this issue only impacts DH ciphersuites and not ECDH ciphersuites.
    This issue affects OpenSSL 1.0.2 which is out of support and no longer receiving public updates. OpenSSL
    1.1.1 is not vulnerable to this issue. Fixed in OpenSSL 1.0.2w (Affected 1.0.2-1.0.2v). (CVE-2020-1968)

  - The X.509 GeneralName type is a generic type for representing different types of names. One of those name
    types is known as EDIPartyName. OpenSSL provides a function GENERAL_NAME_cmp which compares different
    instances of a GENERAL_NAME to see if they are equal or not. This function behaves incorrectly when both
    GENERAL_NAMEs contain an EDIPARTYNAME. A NULL pointer dereference and a crash may occur leading to a
    possible denial of service attack. OpenSSL itself uses the GENERAL_NAME_cmp function for two purposes: 1)
    Comparing CRL distribution point names between an available CRL and a CRL distribution point embedded in
    an X509 certificate 2) When verifying that a timestamp response token signer matches the timestamp
    authority name (exposed via the API functions TS_RESP_verify_response and TS_RESP_verify_token) If an
    attacker can control both items being compared then that attacker could trigger a crash. For example if
    the attacker can trick a client or server into checking a malicious certificate against a malicious CRL
    then this may occur. Note that some applications automatically download CRLs based on a URL embedded in a
    certificate. This checking happens prior to the signatures on the certificate and CRL being verified.
    OpenSSL's s_server, s_client and verify tools have support for the -crl_download option which implements
    automatic CRL downloading and this attack has been demonstrated to work against those tools. Note that an
    unrelated bug means that affected versions of OpenSSL cannot parse or construct correct encodings of
    EDIPARTYNAME. However it is possible to construct a malformed EDIPARTYNAME that OpenSSL's parser will
    accept and hence trigger this attack. All OpenSSL 1.1.1 and 1.0.2 versions are affected by this issue.
    Other OpenSSL releases are out of support and have not been checked. Fixed in OpenSSL 1.1.1i (Affected
    1.1.1-1.1.1h). Fixed in OpenSSL 1.0.2x (Affected 1.0.2-1.0.2w). (CVE-2020-1971)

  - ASN.1 strings are represented internally within OpenSSL as an ASN1_STRING structure which contains a
    buffer holding the string data and a field holding the buffer length. This contrasts with normal C strings
    which are repesented as a buffer for the string data which is terminated with a NUL (0) byte. Although not
    a strict requirement, ASN.1 strings that are parsed using OpenSSL's own d2i functions (and other similar
    parsing functions) as well as any string whose value has been set with the ASN1_STRING_set() function will
    additionally NUL terminate the byte array in the ASN1_STRING structure. However, it is possible for
    applications to directly construct valid ASN1_STRING structures which do not NUL terminate the byte array
    by directly setting the data and length fields in the ASN1_STRING array. This can also happen by using
    the ASN1_STRING_set0() function. Numerous OpenSSL functions that print ASN.1 data have been found to
    assume that the ASN1_STRING byte array will be NUL terminated, even though this is not guaranteed for
    strings that have been directly constructed. Where an application requests an ASN.1 structure to be
    printed, and where that ASN.1 structure contains ASN1_STRINGs that have been directly constructed by the
    application without NUL terminating the data field, then a read buffer overrun can occur. The same thing
    can also occur during name constraints processing of certificates (for example if a certificate has been
    directly constructed by the application instead of loading it via the OpenSSL parsing functions, and the
    certificate contains non NUL terminated ASN1_STRING structures). It can also occur in the
    X509_get1_email(), X509_REQ_get1_email() and X509_get1_ocsp() functions. If a malicious actor can cause an
    application to directly construct an ASN1_STRING and then process it through one of the affected OpenSSL
    functions then this issue could be hit. This might result in a crash (causing a Denial of Service attack).
    It could also result in the disclosure of private memory contents (such as private keys, or sensitive
    plaintext). Fixed in OpenSSL 1.1.1l (Affected 1.1.1-1.1.1k). Fixed in OpenSSL 1.0.2za (Affected
    1.0.2-1.0.2y). (CVE-2021-3712)

  - OpenSSL 1.0.2 supports SSLv2. If a client attempts to negotiate SSLv2 with a server that is configured to
    support both SSLv2 and more recent SSL and TLS versions then a check is made for a version rollback attack
    when unpadding an RSA signature. Clients that support SSL or TLS versions greater than SSLv2 are supposed
    to use a special form of padding. A server that supports greater than SSLv2 is supposed to reject
    connection attempts from a client where this special form of padding is present, because this indicates
    that a version rollback has occurred (i.e. both client and server support greater than SSLv2, and yet this
    is the version that is being requested). The implementation of this padding check inverted the logic so
    that the connection attempt is accepted if the padding is present, and rejected if it is absent. This
    means that such as server will accept a connection if a version rollback attack has occurred. Further the
    server will erroneously reject a connection if a normal SSLv2 connection attempt is made. Only OpenSSL
    1.0.2 servers from version 1.0.2s to 1.0.2x are affected by this issue. In order to be vulnerable a 1.0.2
    server must: 1) have configured SSLv2 support at compile time (this is off by default), 2) have configured
    SSLv2 support at runtime (this is off by default), 3) have configured SSLv2 ciphersuites (these are not in
    the default ciphersuite list) OpenSSL 1.1.1 does not have SSLv2 support and therefore is not vulnerable to
    this issue. The underlying error is in the implementation of the RSA_padding_check_SSLv23() function. This
    also affects the RSA_SSLV23_PADDING padding mode used by various other functions. Although 1.1.1 does not
    support SSLv2 the RSA_padding_check_SSLv23() function still exists, as does the RSA_SSLV23_PADDING padding
    mode. Applications that directly call that function or use that padding mode will encounter this issue.
    However since there is no support for the SSLv2 protocol in 1.1.1 this is considered a bug and not a
    security issue in that version. OpenSSL 1.0.2 is out of support and no longer receiving public updates.
    Premium support customers of OpenSSL 1.0.2 should upgrade to 1.0.2y. Other users should upgrade to 1.1.1j.
    Fixed in OpenSSL 1.0.2y (Affected 1.0.2s-1.0.2x). (CVE-2021-23839)

  - Calls to EVP_CipherUpdate, EVP_EncryptUpdate and EVP_DecryptUpdate may overflow the output length argument
    in some cases where the input length is close to the maximum permissable length for an integer on the
    platform. In such cases the return value from the function call will be 1 (indicating success), but the
    output length value will be negative. This could cause applications to behave incorrectly or crash.
    OpenSSL versions 1.1.1i and below are affected by this issue. Users of these versions should upgrade to
    OpenSSL 1.1.1j. OpenSSL versions 1.0.2x and below are affected by this issue. However OpenSSL 1.0.2 is out
    of support and no longer receiving public updates. Premium support customers of OpenSSL 1.0.2 should
    upgrade to 1.0.2y. Other users should upgrade to 1.1.1j. Fixed in OpenSSL 1.1.1j (Affected 1.1.1-1.1.1i).
    Fixed in OpenSSL 1.0.2y (Affected 1.0.2-1.0.2x). (CVE-2021-23840)

  - The OpenSSL public API function X509_issuer_and_serial_hash() attempts to create a unique hash value based
    on the issuer and serial number data contained within an X509 certificate. However it fails to correctly
    handle any errors that may occur while parsing the issuer field (which might occur if the issuer field is
    maliciously constructed). This may subsequently result in a NULL pointer deref and a crash leading to a
    potential denial of service attack. The function X509_issuer_and_serial_hash() is never directly called by
    OpenSSL itself so applications are only vulnerable if they use this function directly and they use it on
    certificates that may have been obtained from untrusted sources. OpenSSL versions 1.1.1i and below are
    affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1j. OpenSSL versions 1.0.2x
    and below are affected by this issue. However OpenSSL 1.0.2 is out of support and no longer receiving
    public updates. Premium support customers of OpenSSL 1.0.2 should upgrade to 1.0.2y. Other users should
    upgrade to 1.1.1j. Fixed in OpenSSL 1.1.1j (Affected 1.1.1-1.1.1i). Fixed in OpenSSL 1.0.2y (Affected
    1.0.2-1.0.2x). (CVE-2021-23841)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://kb.juniper.net/JSA69715");
  script_set_attribute(attribute:"solution", value:
"Apply the relevant Junos software release referenced in Juniper advisory JSA69715");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-3712");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/09/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/07/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/11/01");

  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:juniper:junos");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("junos_version.nasl");
  script_require_keys("Host/Juniper/JUNOS/Version");

  exit(0);
}

include('junos.inc');
include('junos_kb_cmd_func.inc');


var ver = get_kb_item_or_exit('Host/Juniper/JUNOS/Version');

var vuln_ranges = [
  {'min_ver':'0',    'fixed_ver':'18.4R2-S10'},
  {'min_ver':'19.1', 'fixed_ver':'19.2R1-S9'},
  {'min_ver':'19.2R2', 'fixed_ver':'19.2R3-S5'},
  {'min_ver':'19.3', 'fixed_ver':'19.3R3-S5'},
  {'min_ver':'19.4', 'fixed_ver':'19.4R3-S7'},
  {'min_ver':'20.1', 'fixed_ver':'20.1R3-S3'},
  {'min_ver':'20.2', 'fixed_ver':'20.2R3-S4'},
  {'min_ver':'20.3', 'fixed_ver':'20.3R3-S2'},
  {'min_ver':'20.4', 'fixed_ver':'20.4R3-S1'},
  {'min_ver':'21.1', 'fixed_ver':'21.1R3-S1'},
  {'min_ver':'21.2', 'fixed_ver':'21.2R2-S1', 'fixed_display':'21.2R2-S1, 21.2R3'},
  {'min_ver':'21.3', 'fixed_ver':'21.3R2'}
];

var fix = junos_compare_range(target_version:ver, vuln_ranges:vuln_ranges);
if (empty_or_null(fix)) audit(AUDIT_INST_VER_NOT_VULN, 'Junos OS', ver);

var report = get_report(ver:ver, fix:fix);
security_report_v4(severity:SECURITY_WARNING, port:0, extra:report);