CVE-2020-26572
published 2020-10-06CVE-2020-26572: The TCOS smart card software driver in OpenSC before 0.21.0-rc1 has a stack-based buffer overflow in tcos_decipher.
PriorityP425medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.40%
32.2th percentile
The TCOS smart card software driver in OpenSC before 0.21.0-rc1 has a stack-based buffer overflow in tcos_decipher.
Affected
14 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | debian_linux | — | — |
| debian | opensc | < opensc 0.21.0-1 (bookworm) | opensc 0.21.0-1 (bookworm) |
| fedoraproject | fedora | — | — |
| msrc | cbl2_opensc_0.22.0-1_on_cbl_mariner_2.0 | — | — |
| msrc | cbl_mariner_2.0_arm | — | — |
| msrc | cbl_mariner_2.0_x64 | — | — |
| opensc_project | opensc | <= 0.20.0 | — |
| opensc_project | opensc | >= 0 < 0.21.0-1 | 0.21.0-1 |
| opensc_project | opensc | >= 0 < 0.21.0-1 | 0.21.0-1 |
| opensc_project | opensc | >= 0 < 0.21.0-1 | 0.21.0-1 |
| opensc_project | opensc | >= 0 < 0.21.0-1 | 0.21.0-1 |
| opensc_project | opensc | >= 0 < 0.15.0-1ubuntu1+esm1 | 0.15.0-1ubuntu1+esm1 |
| opensc_project | opensc | >= 0 < 0.17.0-3ubuntu0.1~esm1 | 0.17.0-3ubuntu0.1~esm1 |
| opensc_project | opensc | >= 0 < 0.20.0-3ubuntu0.1~esm1 | 0.20.0-3ubuntu0.1~esm1 |
CVSS provenance
nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
nvdv2.02.1LOWAV:L/AC:L/Au:N/C:N/I:N/A:P
osv6.4MEDIUM
vendor_ubuntu6.4MEDIUM
vendor_debian5.5MEDIUM
vendor_msrc5.5MEDIUM
vendor_redhat5.5MEDIUM
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Ubuntu
OpenSC vulnerabilities
vendor_ubuntu·2022-06-08·CVSS 6.4
CVE-2020-26572 [MEDIUM] OpenSC vulnerabilities
Title: OpenSC vulnerabilities
Summary: Several security issues were fixed in OpenSC.
It was discovered that some OpenSC smart card drivers mishandled memory
when performing certain decoding operations. An attacker could possibly
use this issue to cause a denial of service or other unspecified impact.
This issue only affected Ubuntu 16.04 ESM and Ubuntu 18.04 ESM.
(CVE-2019-15945, CVE-2019-15946)
It was discovered that some OpenSC smart card drivers had buffer overflow
vulnerabilities. An attacker could possibly use this issue to cause a
denial of service or other unspecified impact.
(CVE-2020-26570, CVE-2020-26571, CVE-2020-26572)
Instructions: In general, a standard system update will make all the necessary changes.
Microsoft
The TCOS smart card software driver in OpenSC before 0.21.0-rc1 has a stack-based buffer overflow in tcos_decipher.
vendor_msrc·2020-10-13·CVSS 5.5
CVE-2020-26572 [MEDIUM] CWE-787 The TCOS smart card software driver in OpenSC before 0.21.0-rc1 has a stack-based buffer overflow in tcos_decipher.
The TCOS smart card software driver in OpenSC before 0.21.0-rc1 has a stack-based buffer overflow in tcos_decipher.
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.
Mariner: Mariner
mitre: mitre
Customer Action Required: Yes
Red Hat
opensc: stack-based buffer overflow in tcos_decipher
vendor_redhat·2020-10-06·CVSS 5.5
CVE-2020-26572 [MEDIUM] CWE-121 opensc: stack-based buffer overflow in tcos_decipher
opensc: stack-based buffer overflow in tcos_decipher
The TCOS smart card software driver in OpenSC before 0.21.0-rc1 has a stack-based buffer overflow in tcos_decipher.
Mitigation: This flaw can be mitigated in cases where you can use opensc without the TCOS 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 TCOS driver. With the TCOS 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.
Package: opensc (
Debian
CVE-2020-26572: opensc - The TCOS smart card software driver in OpenSC before 0.21.0-rc1 has a stack-base...
vendor_debian·2020·CVSS 5.5
CVE-2020-26572 [MEDIUM] CVE-2020-26572: opensc - The TCOS smart card software driver in OpenSC before 0.21.0-rc1 has a stack-base...
The TCOS smart card software driver in OpenSC before 0.21.0-rc1 has a stack-based buffer overflow in tcos_decipher.
Scope: local
bookworm: resolved (fixed in 0.21.0-1)
bullseye: resolved (fixed in 0.21.0-1)
forky: resolved (fixed in 0.21.0-1)
sid: resolved (fixed in 0.21.0-1)
trixie: resolved (fixed in 0.21.0-1)
OSV
opensc vulnerabilities
osv·2022-06-08·CVSS 6.4
CVE-2019-15945 [MEDIUM] opensc vulnerabilities
opensc vulnerabilities
It was discovered that some OpenSC smart card drivers mishandled memory
when performing certain decoding operations. An attacker could possibly
use this issue to cause a denial of service or other unspecified impact.
This issue only affected Ubuntu 16.04 ESM and Ubuntu 18.04 ESM.
(CVE-2019-15945, CVE-2019-15946)
It was discovered that some OpenSC smart card drivers had buffer overflow
vulnerabilities. An attacker could possibly use this issue to cause a
denial of service or other unspecified impact.
(CVE-2020-26570, CVE-2020-26571, CVE-2020-26572)
GHSA
GHSA-h2m7-5hj2-cj6c: The TCOS smart card software driver in OpenSC before 0
ghsa_unreviewed·2022-05-24
CVE-2020-26572 [MEDIUM] CWE-787 GHSA-h2m7-5hj2-cj6c: The TCOS smart card software driver in OpenSC before 0
The TCOS smart card software driver in OpenSC before 0.21.0-rc1 has a stack-based buffer overflow in tcos_decipher.
OSV
CVE-2020-26572: The TCOS smart card software driver in OpenSC before 0
osv·2020-10-06·CVSS 5.5
CVE-2020-26572 [MEDIUM] CVE-2020-26572: The TCOS smart card software driver in OpenSC before 0
The TCOS smart card software driver in OpenSC before 0.21.0-rc1 has a stack-based buffer overflow in tcos_decipher.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2020-26572 opensc: stack-based buffer overflow in tcos_decipher
bugzilla·2020-10-07·CVSS 5.5
CVE-2020-26572 [MEDIUM] CVE-2020-26572 opensc: stack-based buffer overflow in tcos_decipher
CVE-2020-26572 opensc: stack-based buffer overflow in tcos_decipher
The TCOS smart card software driver in OpenSC before 0.21.0-rc1 has a stack-based buffer overflow in tcos_decipher.
References:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=22967
https://github.com/OpenSC/OpenSC/commit/9d294de90d1cc66956389856e60b6944b27b4817
Discussion:
Created opensc tracking bugs for this issue:
Affects: epel-6 [bug 1885955]
Affects: fedora-all [bug 1885956]
---
Flaw summary:
In the tcos_decipher() routine of src/libopensc/card-tcos.c, a call to `memcpy()` of size `crgram_len` could overflow past the end of the `sbuf` buffer, causing an out-of-bounds write. This could occur when `crgram_len` is greater than the size of `SC_MAX_APDU_BUFFER_SIZE`. The patch ensures that if `crgram_len` i
Bugzilla
CVE-2020-26572 opensc: stack-based buffer overflow in tcos_decipher [fedora-all]
bugzilla·2020-10-07·CVSS 5.5
CVE-2020-26572 [MEDIUM] CVE-2020-26572 opensc: stack-based buffer overflow in tcos_decipher [fedora-all]
CVE-2020-26572 opensc: stack-based buffer overflow in tcos_decipher [fedora-all]
This is an automatically created tracking bug! It was created to ensure
that one or more security vulnerabilities are fixed in affected versions
of fedora-all.
For comments that are specific to the vulnerability please use bugs filed
against the "Security Response" product referenced in the "Blocks" field.
For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs
When submitting as an update, use the fedpkg template provided in the next
comment(s). This will include the bug IDs of this tracking bug as well as
the relevant top-level CVE bugs.
Please also mention the CVE IDs being fixed in the RPM changelog and the
fedpkg commit message.
NOTE: this issue affects multiple supported versi
Bugzilla
CVE-2020-26572 opensc: stack-based buffer overflow in tcos_decipher [epel-6]
bugzilla·2020-10-07·CVSS 5.5
CVE-2020-26572 [MEDIUM] CVE-2020-26572 opensc: stack-based buffer overflow in tcos_decipher [epel-6]
CVE-2020-26572 opensc: stack-based buffer overflow in tcos_decipher [epel-6]
This is an automatically created tracking bug! It was created to ensure
that one or more security vulnerabilities are fixed in affected versions
of epel-6.
For comments that are specific to the vulnerability please use bugs filed
against the "Security Response" product referenced in the "Blocks" field.
For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs
When submitting as an update, use the fedpkg template provided in the next
comment(s). This will include the bug IDs of this tracking bug as well as
the relevant top-level CVE bugs.
Please also mention the CVE IDs being fixed in the RPM changelog and the
fedpkg commit message.
Discussion:
Use the following template to for the 'fedpk
http://www.openwall.com/lists/oss-security/2020/11/24/4https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=22967https://github.com/OpenSC/OpenSC/commit/9d294de90d1cc66956389856e60b6944b27b4817https://lists.debian.org/debian-lts-announce/2021/11/msg00027.htmlhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EXOHFDMNMO6IDECAGUTB3SJGAGXVRT6S/http://www.openwall.com/lists/oss-security/2020/11/24/4https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=22967https://github.com/OpenSC/OpenSC/commit/9d294de90d1cc66956389856e60b6944b27b4817https://lists.debian.org/debian-lts-announce/2021/11/msg00027.htmlhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EXOHFDMNMO6IDECAGUTB3SJGAGXVRT6S/
2020-10-06
Published