RHSA-2010:0838: Moderate: pki security and enhancement update

First published: Mon Nov 08 2010(Updated: )

Red Hat Certificate System is an enterprise software system designed to<br>manage enterprise public key infrastructure (PKI) deployments. Simple<br>Certificate Enrollment Protocol (SCEP) is a PKI communication protocol<br>used to automatically enroll certificates for network devices.<br>The certificate authority allowed unauthenticated users to request the<br>one-time PIN in an SCEP request to be decrypted. An attacker able to sniff<br>an SCEP request from a network device could request the certificate<br>authority to decrypt the request, allowing them to obtain the one-time<br>PIN. With this update, the certificate authority only handles decryption<br>requests from authenticated registration authorities. (CVE-2010-3868)<br>The certificate authority allowed the one-time PIN used in SCEP requests<br>to be re-used. An attacker possessing a valid SCEP enrollment one-time PIN<br>could use it to generate an unlimited number of certificates.<br>(CVE-2010-3869)<br>The certificate authority used the MD5 hash algorithm to sign all SCEP<br>protocol responses. As MD5 is not collision resistant, an attacker could<br>use this flaw to perform an MD5 chosen-prefix collision attack to generate<br>attack-chosen output signed using the certificate authority's key.<br>(CVE-2004-2761)<br>This update also adds the following enhancements:<br><li> New configuration options for the SCEP server can define the default and</li> allowed encryption and hash algorithms. These options allow disabling uses<br>of the weaker algorithms not required by network devices and prevent<br>possible downgrade attacks. These can be configured by adding the following<br>options to the certificate authority's CS.cfg configuration file:<br>ca.scep.encryptionAlgorithm=DES3<br> ca.scep.allowedEncryptionAlgorithms=DES3<br> ca.scep.hashAlgorithm=SHA1<br> ca.scep.allowedHashAlgorithms=SHA1,SHA256,SHA512<br><li> With this update, the certificate authority's SCEP server is disabled by</li> default. The SCEP server can be enabled by adding the 'ca.scep.enable=true'<br>option to the certificate authority's CS.cfg configuration file.<br><li> A separate key pair can now be configured for use in SCEP communication.</li> Previously, the main certificate authority's key pair was used for SCEP<br>communication too. A designated SCEP key pair can be referenced by adding<br>a new option, ca.scep.nickname=[scep certificate nickname], to the<br>certificate authority's CS.cfg configuration file.<br><li> The certificate authority now allows the size of nonces used in SCEP</li> requests to be restricted by adding a new option, ca.scep.nonceSizeLimit=<br>[number of bytes], to the certificate authority's CS.cfg configuration<br>file. The limit is set to 16 bytes in the default CS.cfg configuration<br>file.<br>All users of Red Hat Certificate System 8 should upgrade to these updated<br>packages, which resolve these issues and add these enhancements.<br>

Never miss a vulnerability like this again

Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.

Read MoreStart Free Trial

• agent/severity
• agent/type
• agent/softwarecombine
• agent/first-publish-date
• agent/last-modified-date
• agent/references
• agent/remedy
• agent/title
• agent/description
• collector/redhat-errata
• source/Red Hat
• anchor-id/RHSA-2010:0838
• agent/software-canonical-lookup
• agent/event
• agent/trending
• agent/tags
• agent/source
• package-manager/redhat