Bug 1885947 (CVE-2020-26570) - CVE-2020-26570 opensc: heap-based buffer overflow in sc_oberthur_read_file
Summary: CVE-2020-26570 opensc: heap-based buffer overflow in sc_oberthur_read_file
Alias: CVE-2020-26570
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 1885948 1885949 1887528
Blocks: 1885958
TreeView+ depends on / blocked
Reported: 2020-10-07 10:51 UTC by Michael Kaplan
Modified: 2021-05-18 20:36 UTC (History)
3 users (show)

Fixed In Version: opensc 0.21.0-rc1
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Last Closed: 2021-05-18 20:36:33 UTC

Attachments (Terms of Use)

Description Michael Kaplan 2020-10-07 10:51:32 UTC
The Oberthur smart card software driver in OpenSC before 0.21.0-rc1 has a heap-based buffer overflow in sc_oberthur_read_file.


Comment 1 Michael Kaplan 2020-10-07 10:52:19 UTC
Created opensc tracking bugs for this issue:

Affects: epel-6 [bug 1885949]
Affects: fedora-all [bug 1885948]

Comment 2 Todd Cullum 2020-10-08 19:35:29 UTC
Flaw summary:
sc_oberthur_read_file() in src/libopensc/pkcs15-oberthur.c attempts to read an invalid record from the card reader APDU interface by reading a record greater than file->record_count, causing an out-of-bounds write.

Comment 5 Todd Cullum 2020-10-12 18:25:48 UTC

This flaw can be mitigated in cases where you can use opensc without the Oberthur driver enabled. In such cases, the vulnerable driver can be disabled by specifying them in /etc/opensc.conf card_drivers field in allowlist fashion.
One such example:

app default {
   card_drivers = cac, cac1, PIV-II;

This would only enable the cac, cac1, and PIV-II smart card drivers, and all others would be disabled, including the Oberthur driver. With the Oberthur driver disabled, this flaw is mitigated. It is important to list all drivers that you need in the card_drivers field so that they are not disabled too.

Comment 7 errata-xmlrpc 2021-05-18 13:35:04 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:1600 https://access.redhat.com/errata/RHSA-2021:1600

Comment 8 Product Security DevOps Team 2021-05-18 20:36:33 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):


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