“);
replaceTable = $t(tmp).find(“table”);
if (!replaceTable.hasClass(“cisco-data-table-small”)) { replaceTable.addClass(“cisco-data-table-small”); }
if (replaceTable.hasClass(“cisco-data-table”)) { replaceTable.removeClass(“cisco-data-table”); }
if (replaceTable.attr(“id”)) { replaceTable.attr(“id”,replaceTable.attr(“id”)+”-small”); }
$t(this).find(“tr”).each(function (index) {
currentRowSpanCounter = 0;
if (!$t(this).hasClass(“data-table-header-row”) && !$t(this).hasClass(“data-table-section-header-row”)) {

$t(this).find(“th,td”).each(function (index) {
colIndex = index;

if (rowSpanIndexes.length > 0) {
for (r = 0; r 0) {
if (colIndex == r) {
replaceTable.find(“tbody:first”).append(“

“)
if ((rowCounter) % 2 == 0) {
replaceTable.find(“tbody:first > tr:last”).addClass(“data-table-alternate-row”);
}
}
colIndex = colIndex + 1;
}
}
}
colIndex = colIndex – currentRowSpanCounter;
if ($t(this).attr(“rowspan”) != undefined && $t(this).attr(“rowspan”) > 1) {
rowSpanIndexes[colIndex] = $t(this).attr(“rowspan”);
rowSpanCellArray[colIndex] = $t(this);
currentRowSpanCounter++;
}
if (!$t(this).hasClass(“data-table-caption-cell”) && !$t(this).hasClass(“data-table-header-cell”)) {
for(var cidx = index-1; cidx >=0; cidx–)
{
var cidxe = $t(this).parent().children()[cidx];
var cidxspan = $t(cidxe).attr(“colspan”);
if(cidxspan != undefined && cidxspan > 1)
{
colIndex = colIndex + (cidxspan – 1)
}
}

replaceTable.find(“tbody:first”).append(“

“)
if ((rowCounter) % 2 == 0) {
replaceTable.find(“tbody:first > tr:last”).addClass(“data-table-alternate-row”);
}
if ($t(this).attr(“colspan”) != undefined && $t(this).attr(“colspan”) > 1) {
var colSpan = $t(this).attr(“colspan”);
var cs = 1
do{
if ($t(this).attr(“rowspan”) != undefined && $t(this).attr(“rowspan”) > 1) {
rowSpanIndexes[cs+colIndex] = $t(this).attr(“rowspan”);
rowSpanCellArray[cs+colIndex] = $t(this);
currentRowSpanCounter++;
}
replaceTable.find(“tbody:first”).append(“

“)
if ((rowCounter) % 2 == 0) {
replaceTable.find(“tbody:first > tr:last”).addClass(“data-table-alternate-row”);
}
cs++;
}while(cs

“)
var newCell = $t(replaceTable).find(“tbody > tr:last > td:last”);
var newRow = $t(replaceTable).find(“tbody > tr:last”);
newRow.attr(“style”, $t(this).parent().attr(“style”));
newRow.addClass($t(this).parent().attr(“class”));
newCell.attr(“colspan”, 2);
newCell.attr(“style”, $t(this).attr(“style”));
newCell.addClass($t(this).attr(“class”));
}

});
rowCounter++;

}
else {
rowCounter = 1;
$t(this).find(“td,th”).each(function (index) {
colIndex = index;
if (rowSpanIndexes.length > 0) {
for (r = 0; r 0) { colIndex = colIndex + 1; }
}
}
if ($t(this).hasClass(“data-table-caption-cell”)) {

var captionColSpan = $t(this).attr(“colspan”);
for(var cidx = index-1; cidx >=0; cidx–)
{
var cidxe = $t(this).parent().children()[cidx];
var cidxspan = $t(cidxe).attr(“colspan”);
if(cidxspan != undefined && cidxspan > 1)
{
colIndex = colIndex + (cidxspan – 1)
}
}
currentCellCaption[colIndex] = $t(this).html();
for (c = colIndex + 1; c

“)
var newCell = $t(replaceTable).find(“tbody > tr:last > td:last”);
var newRow = $t(replaceTable).find(“tbody > tr:last”);
newRow.attr(“style”, $t(this).parent().attr(“style”));
newRow.addClass($t(this).parent().attr(“class”));
newCell.attr(“colspan”, 2);
newCell.attr(“style”, $t(this).attr(“style”));
newCell.addClass($t(this).attr(“class”));

}
});
}
for (r = 0; r 0) { rowSpanIndexes[r]–; }
}
});
scrollTable = false;
}
catch(tblexc){
console.log(tblexec);
scrollTable = true;
}
}

while (newIndex != -1) {
if ($t(this).hasClass(“cisco-data-table”) && !scrollTable) {
var c4 = replaceTable[0].outerHTML;
c3 = c2.replace(escTable, escTable + c4);
tmp = null;
}
else {
c3 = c2.replace(escTable, ‘

‘ + escTable + ‘

‘);
}

content = content.substring(0, newIndex) + c3;
newIndex = content.indexOf(escTable, newIndex + escTable.length);
if(newIndex != -1){
c2 = content.substring(newIndex,content.length);
}
}
}
if (update) {
parent.html(content);
}
});
});

$t(“.collapsible-link-list h2.ud-section-heading”).click(function () {
$t(this).toggleClass(“open”);
return false;
});
$t(“.ud-side-link-list h2.ud-section-heading”).click(function () {
$t(this).toggleClass(“open”);
return false;
});
$t(“.ud-main-link-list h2.ud-section-heading”).click(function () {
$t(this).toggleClass(“open”);
return false;
});

$t(“a.tableToggler”).click(function () {
if($t(this).prev(“table”).find(“tr:eq(3)”).length==0)
{
$t(this).toggle();
return;
}
if($t(this).text() == “Show Complete History…”)
{
$t(this).html(“Show Less”);
}
else
{
$t(this).html(“Show Complete History…”);
}
var $tr = $t(this).prev(“table”).find(“tr:eq(3)”).toggle();
$tr.nextAll().toggle();
}).prev(“table”).find(“tr:eq(3)”).show().end().end().trigger(‘click’);

$t(“a.relatedcontenttoggle”).click(function () {
if ($t(this).hasClass(“less”)) {
$t(this).removeClass(“less”);
$t(this).parent().find(“div.flexrow:eq(9)”).nextAll().addClass(“relatedoverflow-hidden”);
$t(this).text(“Show All “+relatedCount+”…”);
} else {
$t(this).addClass(“less”);
$t(this).parent().find(“div.flexrow:eq(9)”).nextAll().removeClass(“relatedoverflow-hidden”);
$t(this).text(“Show Less”);
}
return false;
});

//Dialog Handlers
hideDisalogs();

$t(window).resize(function(){
hideDisalogs();
});

$t(‘body’).click(function (e) {
hideDisalogs();
});

//Begin CVE
$t(‘.cves’).click(function (e) {
e.stopPropagation();
$t(“.cves”).show();
});

$t(‘.closeCVE’).click(function (e) {
e.stopPropagation();
$t(“.cves”).hide();
return false;
});

$t(‘.showCVE’).click(function (e) {
hideDisalogs();
e.stopPropagation();
var $cveIWidthDiv = $t(this).parent().parent().parent().find(“.cveParentIWidth”);
var $cveparentDiv = $t(this).parent().parent().parent().find(“.cves”);
var $content = $t(this).parent().parent().parent().find(“#fullcvecontent_content”);

var $this = $t(this);

showDialog($this, $cveIWidthDiv, $cveparentDiv, $content);

return false;
});
//End CVE

//Begin CWE
$t(‘.cwes’).click(function (e) {
e.stopPropagation();
$t(“.cwes”).show();
});

$t(‘.closeCWE’).click(function (e) {
e.stopPropagation();
$t(“.cwes”).hide();
return false;
})

$t(‘.showCWE’).click(function (e) {
hideDisalogs();
e.stopPropagation();
var $cveIWidthDiv = $t(this).parent().parent().parent().parent().find(“.cweParentIWidth”);
var $cveparentDiv = $t(this).parent().parent().parent().parent().find(“.cwes”);
var $content = $t(this).parent().parent().parent().parent().find(“#fullcwecontent_content”);

var $this = $t(this);

showDialog($this, $cveIWidthDiv, $cveparentDiv, $content);

return false;
});
//End CWE

//Begin DDTS Bug IDs
$t(‘.ddts’).click(function (e) {
e.stopPropagation();
$t(“.ddts”).show();
});

$t(‘.closeDDTS’).click(function (e) {
e.stopPropagation();
$t(“.ddts”).hide();
return false;
});

$t(‘.showDDTS’).click(function (e) {
hideDisalogs();
e.stopPropagation();
var $cveIWidthDiv = $t(this).parent().parent().parent().find(“.ddtsParentIWidth”);
var $cveparentDiv = $t(this).parent().parent().parent().find(“.ddts”);
var $content = $t(this).parent().parent().parent().find(“#fullddtscontent_content”);
var $this = $t(this);

showDialog($this, $cveIWidthDiv, $cveparentDiv, $content);

return false;
});
//End DDTS Bug IDs

});

function hideDisalogs() {
$t(“.cves”).hide();
$t(“.cwes”).hide();
$t(“.ddts”).hide();
}

function showDialog($this, $cveIWidthDiv, $cveparentDiv, $content) {
$cveIWidthDiv.html(“”);

var tempCVEArray = ($content.text()).split(“,”);
var totalCVE = tempCVEArray.length;
var parentWidth;
var ColclassName;
var colWidth;
var limitPerColumn = 0;
if (totalCVE “);
for (i = 0; i ” + tempCVEArray[i] + “”);
}
}

if (totalCVE > 20 && totalCVE “);
for (i = 0; i ” + tempCVEArray[i] + “”);
}

for (j = 20; j ” + tempCVEArray[j] + “”);
}
}

if ($t(window).width() > 768) {
if (totalCVE > 40 && totalCVE “);

for (i = 0; i ” + tempCVEArray[i] + “”);
}

for (j = 20; j ” + tempCVEArray[j] + “”);
}

for (k = 40; k ” + tempCVEArray[k] + “”);
}

}

if (totalCVE > 60) {
ColclassName = “threeCol”;
colWidth = “33.33%”;
limitPerColumn = parseInt(totalCVE / 3);
var lim_remainder = totalCVE % 3;
var lim1 = limitPerColumn;
var lim2 = 2 * limitPerColumn;;
var lim3 = totalCVE;
if (lim_remainder == 1) {
lim1 = limitPerColumn + 1;
lim2 = limitPerColumn + lim1;
}
if (lim_remainder == 2) {
lim1 = limitPerColumn + 1;
lim2 = limitPerColumn + lim1 + 1;
}

$cveIWidthDiv.append(” “);
$cveIWidthDiv.css(“overflow”, “auto”);

for (i = 0; i ” + tempCVEArray[i] + “”);
}
for (j = lim1; j ” + tempCVEArray[j] + “”);
}
for (k = lim2; k ” + tempCVEArray[k] + “”);
}

}
}

if ($t(window).width() 40) {
ColclassName = “twoCol”;
colWidth = “50%”;
parentWidth = “300px”;
$cveparentDiv.css(“width”, parentWidth);
limitPerColumn = parseInt(totalCVE / 2);
var lim_remainder = totalCVE % 2;
var lim1 = limitPerColumn;
var lim2 = totalCVE;
if (lim_remainder == 1) {
lim1 = limitPerColumn + 1;
}
$cveIWidthDiv.append(” “);
$cveIWidthDiv.css(“overflow”, “auto”);
for (i = 0; i ” + tempCVEArray[i] + “”);
}

for (j = lim1; j ” + tempCVEArray[j] + “”);
}

}
}

$cveparentDiv.slideDown(300);

var cvwidth = 40;
$cveparentDiv.find(“.cvecolumn”).each(function () {
cvwidth = cvwidth + $t(this).width() + 35;
});

$cveparentDiv.css(“width”, cvwidth);

if ($t(window).width() > 768) {
var cveboxheight = 300;
var scrltop = $cveparentDiv.offset().top – 50;
$t(‘html, body’).animate({
scrollTop: scrltop
}, 500);
$cveparentDiv.transpose
}
}

function cvssToClip(){
var target = document.getElementById(“hdncvssvector”);
var currentFocus = document.activeElement;
target.focus();
target.setSelectionRange(0, target.value.length);
// copy the selection
var succeed;
try {
succeed = document.execCommand(“copy”,false,target.value);
} catch(e) {
succeed = false;
}
// restore original focus
if (currentFocus && typeof currentFocus.focus === “function”) {
currentFocus.focus();
}
}

‘+h2+’

‘ + moretext + ‘‘;
$t(this).html(html);
$t(this).find(“div.full”).toggle();
}
}
}
catch(exc){
console.log(exc);
$t(this).html(htmlBase);
}

});

$t(“.morelink”).click(function () {
if ($t(this).hasClass(“less”)) {
$t(this).removeClass(“less”);
$t(this).text(moretext);
} else {
$t(this).addClass(“less”);
$t(this).text(lesstext);
}
$t(this).parent().find(“div.snippet”).toggle();
$t(this).parent().find(“div.full”).toggle();
return false;
});

//$t(“.btnShowMoreRows”).click(function () {
//$t(‘table’).find(‘tr:gt(3)’).toggle();
//});

var rowCounter = 1;
var rowSpanIndexes = [];
var adjustedIndex = 0;
var currentRowSpanCounter = 0;
var currentCellCaption = [];
var colIndex = 0;
var rowSpanCellArray = [];

$t(‘#ud-master-container’).find(‘table’).not($t(‘#ud-revision-history’).find(‘table’)).parent().each(function () {
var parent = $t(this);//.parent();
var content = $t(this).html();//.parent().html();
var update = false;
var tblStrings = “”;
parent.find(‘table’).each(function () {
update = true;
var escTable = $t(this)[0].outerHTML;
var newIndex = content.indexOf(escTable);
if (tblStrings.indexOf(escTable) == -1) {
currentCellCaption = [0];
tblStrings += escTable;
var c2 = content.substring(newIndex);
var c3 = c2;
var scrollTable = false;
if ($t(this).hasClass(“cisco-data-table”)) {
try{
rowSpanIndexes = [];
rowCounter = 1;
var tmp = $t(document.createElement(‘div’))
$t(this).clone().appendTo(tmp);
var replaceTable = $t(tmp).find(“table”);
replaceTable.find(“tr,td,tbody,thead”).remove();
replaceTable.append(“

” + currentCellCaption[r] + “ ” + $t(rowSpanCellArray[r]).html() + “
” + currentCellCaption[colIndex] + “ ” + $t(this).html() + “
” + currentCellCaption[cs+colIndex] + “ ” + $t(this).html() + “
” + $t(this).html() + “ ” + $t(this).html() + “
Product Cisco Bug ID Fixed Release Availability
Cisco WebEx Business Suite (including Meeting Center, Training Center, Event Center, Support Center) CSCvh10981 Remediation has been completed. (15-Jan-2018)
Cisco WebEx Meetings CSCvh10981 Remediation has been completed. (15-Jan-2018)
Cisco WebEx Messenger CSCvh25064 Remediation has been completed. (15-Jan-2018)
Cisco ACE 4710 Application Control Engine Appliance CSCvg74693 No fix will be provided for this product. 1
Cisco ACE30 Application Control Engine Module CSCvg74693 No fix will be provided for this product. 2
Cisco Adaptive Security Appliance (ASA) – ASA 5505, 5510, 5520, 5540, and 5550 CSCvg97652 9.1.7.21 (5-Jan-2018)
9.2.4.25 (8-Jan-2018)
Cisco SSL Appliance CSCvh00296 3.12.2.1 (18-May-2018)

1 Cisco ACE 4710 Application Control Engine Appliance entered the end-of-life cycle on July 26, 2013. For reference, see the End-of-Sale and End-of-Life Announcement.
2 Cisco ACE30 Application Control Engine Module entered the end-of-life cycle on July 26, 2013. For reference, see the End-of-Sale and End-of-Life Announcement.

No other Cisco products are currently known to be affected by these vulnerabilities.

Cisco has confirmed that these vulnerabilities do not affect the following products:

Cisco Cloud Hosted Services

  • Cisco Cloud Web Security (CWS)
  • Cisco Spark
  • Cisco Umbrella

Network Application, Service, and Acceleration

  • Cisco Wide Area Application Services (WAAS)

Network and Content Security Devices

  • Cisco Adaptive Security Appliance (ASA) – All models not listed in the Vulnerable Products section
  • Cisco ASA Next-Generation Firewall Services
  • Cisco Content Security Management Appliance (SMA)
  • Cisco Email Security Appliance (ESA)
  • Cisco Firepower 2100 Series
  • Cisco Firepower 4100 Series
  • Cisco Firepower 7000 Series
  • Cisco Firepower 8000 Series
  • Cisco Firepower 9300 Security Appliance
  • Cisco Identity Services Engine (ISE)
  • Cisco Web Security Appliance (WSA)

Routing and Switching – Enterprise and Service Provider

  • Cisco VPN Internal Service Module for ISR (VPN ISM)

Details

  • Bleichenbacher’s attack is an adaptive chosen-ciphertext attack against RSA PKCS#1 v1.5 encryption block formatting. Daniel Bleichenbacher originally performed this attack against the RSA key exchange on Secure Sockets Layer (SSL) Version 3.0.

    The attack relies on the presence of a side channel indicating, for any chosen ciphertext, whether the corresponding plaintext has the correct format according to the RSA PKCS#1 v1.5 standard. An attacker could exploit this side channel as an oracle, iteratively constructing crafted TLS messages. Eventually the attacker might be able to recover the plaintext for a given TLS session.

    The new research focused on identifying current TLS implementations affected by the classic Bleichenbacher attack or those affected by newly introduced variations. These new variations use the overall TCP connection state as a possible side channel and use a nonstandard, abbreviated TLS message flow.

    The following vulnerabilities were identified based on this research:

    Cavium SSL SDK Bleichenbacher Attack Information Disclosure Vulnerability

    A vulnerability in the TLS protocol implementation of Cavium SSL Software Development Kits (SDKs) could allow an unauthenticated, remote attacker to access sensitive information.

    The vulnerability is due to improper implementation of countermeasures against the Bleichenbacher attack for cipher suites that rely on RSA for key exchange. An attacker could exploit this vulnerability by sending crafted TLS messages to the device, which would act as an oracle and allow the attacker to carry out a chosen-ciphertext attack.

    This vulnerability has been assigned the following CVE ID: CVE-2017-17428.

    Legacy Cisco ASA 5500 Series Bleichenbacher Attack Information Disclosure Vulnerability

    A vulnerability in the TLS protocol implementation of legacy Cisco ASA 5500 Series (ASA 5505, 5510, 5520, 5540, and 5550) devices could allow an unauthenticated, remote attacker to access sensitive information.

    The vulnerability is due to improper implementation of countermeasures against the Bleichenbacher attack for cipher suites that rely on RSA for key exchange. An attacker could exploit this vulnerability by sending crafted TLS messages to the device, which would act as an oracle and allow the attacker to carry out a chosen-ciphertext attack.

    This vulnerability affects the listed ASA models when they are using a 2048-bit RSA key.

    This vulnerability has been assigned the following CVE ID: CVE-2017-12373.

    SSL Visibility Bleichenbacher Attack Information Disclosure Vulnerability

    A vulnerability in the TLS protocol implementation of Cisco SSL Appliance (Bluecoat SSL Visibility OEM appliance) could allow an
    unauthenticated, remote attacker to access sensitive information.

    The vulnerability is due to improper implementation of countermeasures
    against the Bleichenbacher attack for cipher suites that rely on RSA for
    key exchange. An attacker could exploit this vulnerability by sending
    crafted TLS messages to the device, which would act as an oracle and
    allow the attacker to carry out a chosen-ciphertext attack.

    This vulnerability has been assigned the following CVE ID: CVE-2017-15533.


Workarounds

  • Disabling use of TLS ciphers that rely on RSA for key exchange is a possible mitigation for these vulnerabilities. It is applicable only to products that support other types of ciphers, such as those based on Diffie-Hellman key exchange. This mitigation may have an impact on interoperability with legacy clients that do not support these ciphers. This mitigation is not applicable to Cisco Application Control Engine (ACE).

    For potential workarounds on a specific Cisco product, refer to the relevant Cisco bug, which is available from the Cisco Bug Search Tool.

Fixed Software

  • For information about fixed software releases, consult the Cisco bug ID(s) at the top of this advisory. Questions concerning the WebEx environment can be directed to the Cisco Technical Assistance Center (TAC).

    When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories and Alerts page, to determine exposure and a complete upgrade solution.

    In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco TAC or their contracted maintenance providers.

Exploitation and Public Announcements

  • The Cisco Product Security Incident Response Team (PSIRT) is not aware of any malicious use of the vulnerabilities that are described in this advisory.

Source

  • Cisco would like to thank Hanno Böck, Juraj Somorovsky of Ruhr-Universität Bochum/Hackmanit GmbH, Craig Young of Tripwire VERT, and Dirk Wetter of testssl.sh/Dr. Wetter IT-Consulting for reporting these vulnerabilities.