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CVE detail

CVE-2021-3450

The X509_V_FLAG_X509_STRICT flag enables additional security checks of the certificates present in a certificate chain. It is not set by default. Starting from OpenSSL version 1.1.1h a check to disallow certificates in the chain that have explicitly encoded elliptic curve parameters was added as an additional strict check. An error in the implementation of this check meant that the result of a previous check to confirm that certificates in the chain are valid CA certificates was overwritten. This effectively bypasses the check that non-CA certificates must not be able to issue other certificates. If a "purpose" has been configured then there is a subsequent opportunity for checks that the certificate is a valid CA. All of the named "purpose" values implemented in libcrypto perform this check. Therefore, where a purpose is set the certificate chain will still be rejected even when the strict flag has been used. A purpose is set by default in libssl client and server certificate verification routines, but it can be overridden or removed by an application. In order to be affected, an application must explicitly set the X509_V_FLAG_X509_STRICT verification flag and either not set a purpose for the certificate verification or, in the case of TLS client or server applications, override the default purpose. OpenSSL versions 1.1.1h and newer are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1k. OpenSSL 1.0.2 is not impacted by this issue. Fixed in OpenSSL 1.1.1k (Affected 1.1.1h-1.1.1j).

CVSS 7.4 · HighBuzz score 25.4

Buzz score

Why this CVE is surfacing

Buzz score total 25.4

This all-time snapshot uses the same composite formula as Trending across a 30-year evidence window, rather than a current rolling window.

Buzz score components · mention 13.9 · diversity 11.5 · KEV 0.0 · OTX 0.0 · PoC 0.0
Mention score
13.9
3 evidence mentions in the snapshot
Diversity score
11.5
3 sources across 2 categories
KEV score
0.0
No KEV entry observed
OTX score
0.0
0 OTX pulses
PoC score
0.0
0 repos · best confidence N/A
Best PoC traction
0
Maximum stars on a matched PoC repo

Why it matters now

Mention timeline

Total mentions
0
within the 30d window
Peak daily
0
highest bucket

Evidence

Source links by recency

Newest mentions first
3 source links · newest first
  • 5th April – Threat Intelligence ReportCheck Point Research

    For the latest discoveries in cyber research for the week of 5th April, please download our Threat Intelligence Bulletin. Top Attacks and Breaches Personal information of some 553 million Facebook users from 100 countries has been stolen and published online for free in a hacking forum. The records include full name, Facebook ID, phone number, […]

    vendorresearch.checkpoint.comApr 5, 2021, 4:14 PM
  • OpenSSL Project released 1.1.1k version to fix two High-severity flawsSecurity Affairs

    The OpenSSL Project addresses two high-severity vulnerabilities, including one related to verifying a certificate chain and one that can trigger a DoS condition. The OpenSSL Project this week released version 1.1.1k to address two high-severity vulnerabilities, respectively tracked as CVE-2021-3450 and CVE-2021-3449. The CVE-2021-3449 vulnerability could be exploited to trigger a DoS condition by sending a […]

    newssecurityaffairs.comMar 25, 2021, 9:57 PM
  • OpenSSL 1.1.1k Patches Two High-Severity VulnerabilitiesSecurityWeek

    The OpenSSL Project on Thursday announced the release of version 1.1.1k, which patches two high-severity vulnerabilities, including one related to verifying a certificate chain and one that can lead to a server crash. The first security hole, tracked as CVE-2021-3450 , has been described as a “problem with verifying a certificate chain when using the X509_V_FLAG_X509_STRICT flag.” The flaw was discovered by researchers at Akamai. “Starting from OpenSSL version 1.1.1h a check to disallow certificates in the chain that have explicitly encoded elliptic curve parameters was added as an additional strict check. An error in the implementation of this check meant that the result of a previous check to confirm that certificates in the chain are valid CA certificates was overwritten. This effectively bypasses the check that non-CA certificates must not be able to issue other certificates,” the OpenSSL Project explained in its advisory. The second vulnerability, tracked as CVE-2021-3449 and dis…

    newswww.securityweek.comMar 25, 2021, 3:16 PM

Exploit code

Public exploit repository references

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0 repository references · best confidence N/A · max 0 stars
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Related records

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