Bug 1995623 (CVE-2021-3711)
Summary: | CVE-2021-3711 openssl: SM2 Decryption Buffer Overflow | ||
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Product: | [Other] Security Response | Reporter: | Cedric Buissart <cbuissar> |
Component: | vulnerability | Assignee: | Red Hat Product Security <security-response-team> |
Status: | CLOSED ERRATA | QA Contact: | |
Severity: | high | Docs Contact: | |
Priority: | high | ||
Version: | unspecified | CC: | bdettelb, caswilli, cfergeau, crypto-team, csutherl, dbelyavs, erik-fedora, fidencio, gghezzo, gparvin, gzaronik, jclere, jramanat, jwon, kaycoth, krathod, ktietz, marcandre.lureau, michal.skrivanek, mperina, mturk, nobody, pjindal, psegedy, redhat-bugzilla, rh-spice-bugs, rjones, sahana, sbonazzo, security-response-team, stcannon, szappis, tm, tomckay, vmugicag |
Target Milestone: | --- | Keywords: | Security |
Target Release: | --- | ||
Hardware: | All | ||
OS: | Linux | ||
Whiteboard: | |||
Fixed In Version: | openssl 1.1.1l | Doc Type: | If docs needed, set a value |
Doc Text: |
A flaw was found in openssl. A miscalculation of a buffer size was found in openssl's SM2 decryption function, allowing up to 62 arbitrary bytes to be written outside of the buffer. A remote attacker could use this flaw to crash an application supporting SM2 signature or encryption algorithm, or, possibly, execute arbitrary code with the permissions of the user running that application. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
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Story Points: | --- |
Clone Of: | Environment: | ||
Last Closed: | 2021-11-11 18:58:15 UTC | Type: | --- |
Regression: | --- | Mount Type: | --- |
Documentation: | --- | CRM: | |
Verified Versions: | Category: | --- | |
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
Cloudforms Team: | --- | Target Upstream Version: | |
Embargoed: | |||
Bug Depends On: | 1995626, 1995627, 1995628, 1995629, 1997210, 1997211, 1997212, 1997222 | ||
Bug Blocks: | 1995569 |
Description
Cedric Buissart
2021-08-19 14:08:25 UTC
@cbuissar Hi Cedric, I'm not sure if this CVE is really applicable to RHEL, as we compile with 'no-sm2' as a config option, and therefore do not support it. Let me know what you think. Thank you. Thanks Sahana, Yes, that seems to be correct, I can't find references to sm2 functions in the binaries. Let me have just one more look and I will close the BZs (all 5) as NOTABUG. However, as a side note: shouldn't we remove openssl's SM2 man page if we don't compile it in ? ( /usr/share/man/man7/SM2.7ssl.gz is part of the openssl package, and contains code example to use openssl's SM2 encryption) Flaw description: SM2 is an signature and encryption algorithm (see `man sm2` for details) Given an SM2 encrypted message, openssl can calculate the expected length of the clear text version of that message. This is used by applications so that they can allocate the correct amount of memory to store the decrypted message. It was found that a specially crafted SM2 message could trick openssl into calculating an incorrect, shorter, length. This would result in applications using openssl's SM2 decryption functionality to allocate insufficient memory. When the actual decryption happens, up to 62 arbitrary bytes could be written beyond the allocated buffer, corrupting the application's memory. This is likely to crash the application. It might also be feasible, depending on the application, to gain control of the execution. On openssl version 1.1.1, to manually verify is a given openssl package provides SM2 : $ openssl list -public-key-algorithms And look for 'sm2' in the output. This should be sufficient to defined whether it supports sm2 or not. Version 1.0.2 and older to not have support for the `list` command, but do not support SM2 either. Upstream fix, for the 1.1.1 branch : https://github.com/openssl/openssl/commit/59f5e75f3bced8fc0e130d72a3f582cf7b480b46 Created mingw-openssl tracking bugs for this issue: Affects: fedora-all [bug 1997212] Created openssl tracking bugs for this issue: Affects: fedora-all [bug 1997210] Created openssl11 tracking bugs for this issue: Affects: epel-7 [bug 1997211] This issue has been addressed in the following products: Red Hat Advanced Cluster Management for Kubernetes 2.4 for RHEL 8 Via RHSA-2021:4618 https://access.redhat.com/errata/RHSA-2021:4618 This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2021-3711 |