Bug 908234 (CVE-2013-1620) - CVE-2013-1620 nss: TLS CBC padding timing attack
Summary: CVE-2013-1620 nss: TLS CBC padding timing attack
Alias: CVE-2013-1620
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 908257 918870 918872 918874 918875
Blocks: 907592
TreeView+ depends on / blocked
Reported: 2013-02-06 08:44 UTC by Huzaifa S. Sidhpurwala
Modified: 2021-02-17 08:05 UTC (History)
4 users (show)

Fixed In Version: nss 3.14.3
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2016-06-10 21:23:17 UTC

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Mozilla Foundation 822365 0 None None None 2019-02-07 11:48:11 UTC
Red Hat Product Errata RHSA-2013:1135 0 normal SHIPPED_LIVE Moderate: nss and nspr security, bug fix, and enhancement update 2013-08-05 19:51:35 UTC
Red Hat Product Errata RHSA-2013:1144 0 normal SHIPPED_LIVE Moderate: nss, nss-util, nss-softokn, and nspr security update 2013-08-07 21:48:32 UTC
Red Hat Product Errata RHSA-2013:1181 0 normal SHIPPED_LIVE Moderate: rhev-hypervisor6 security and bug fix update 2013-08-27 22:53:35 UTC

Description Huzaifa S. Sidhpurwala 2013-02-06 08:44:35 UTC
A flaw in how TLS/DTLS, when CBC-mode encryption is used, communicates was reported.  This vulnerability can allow for a Man-in-the-Middle attacker to recover plaintext from a TLS/DTLS connection, when CBC-mode encryption is used.

This flaw is in the TLS specification, and not a bug in a specific implementation (as such, it affects nearly all implementations).  As such, it affects all TLS and DTLS implementations that are compliant with TLS 1.1 or 1.2, or with DTLS 1.0 or 1.2.  It also applies to implementations of SSL 3.0 and TLS 1.0 that incorporate countermeasures to deal with previous padding oracle attacks.  All TLS/DTLS ciphersuites that include CBC-mode encryption are potentially vulnerable.

To perform a successful attack, when TLS is used, a large number of TLS sessions are required (target plaintext must be sent repeatedly in the same position in the plaintext stream across the sessions).  For DTLS, a successful attack can be carried out in a single session.  The attacker must also be located close to the machine being attacked.

Further details are noted in the paper:


Currently Mozilla is working on final NSS fixes:


External References:


Comment 1 Huzaifa S. Sidhpurwala 2013-02-06 09:31:31 UTC
Created nss tracking bugs for this issue

Affects: fedora-all [bug 908257]

Comment 4 Tomas Hoger 2013-02-28 07:15:05 UTC
Fixed upstream in nss and nss-softoken 3.14.3:


Comment 6 errata-xmlrpc 2013-08-05 15:54:35 UTC
This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2013:1135 https://rhn.redhat.com/errata/RHSA-2013-1135.html

Comment 7 errata-xmlrpc 2013-08-07 17:50:20 UTC
This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2013:1144 https://rhn.redhat.com/errata/RHSA-2013-1144.html

Comment 8 errata-xmlrpc 2013-08-27 18:54:21 UTC
This issue has been addressed in following products:

  RHEV-H and Agents for RHEL-6

Via RHSA-2013:1181 https://rhn.redhat.com/errata/RHSA-2013-1181.html

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