Vulnerability Details : CVE-2021-3505
A flaw was found in libtpms in versions before 0.8.0. The TPM 2 implementation returns 2048 bit keys with ~1984 bit strength due to a bug in the TCG specification. The bug is in the key creation algorithm in RsaAdjustPrimeCandidate(), which is called before the prime number check. The highest threat from this vulnerability is to data confidentiality.
Products affected by CVE-2021-3505
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:advanced_virtualization:*:*:*
- cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
- cpe:2.3:a:libtpms_project:libtpms:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-3505
0.05%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 20 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-3505
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
2.1
|
LOW | AV:L/AC:L/Au:N/C:P/I:N/A:N |
3.9
|
2.9
|
NIST | |
|
5.5
|
MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
1.8
|
3.6
|
NIST |
CWE ids for CVE-2021-3505
-
The product uses an algorithm or scheme that produces insufficient entropy, leaving patterns or clusters of values that are more likely to occur than others.Assigned by: secalert@redhat.com (Primary)
References for CVE-2021-3505
-
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NUCZX4S53TUNTSGTCRDNOQZV2V2RI4RJ/
[SECURITY] Fedora 33 Update: libtpms-0.8.2-0.20210426git729fc6a4ca.fc33 - package-announce - Fedora Mailing-ListsMailing List;Third Party Advisory
-
https://bugzilla.redhat.com/show_bug.cgi?id=1950046
1950046 – (CVE-2021-3505) CVE-2021-3505 libtpms: RSA keys weaker than expectedIssue Tracking;Patch;Third Party Advisory
-
https://github.com/stefanberger/libtpms/issues/183
[libtpms 0.7] TPM2_CreatePrimary creates prime numbers with 32 zero bits · Issue #183 · stefanberger/libtpms · GitHubExploit;Patch;Third Party Advisory
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