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CVE detail

CVE-2021-23840

Calls to EVP_CipherUpdate, EVP_EncryptUpdate and EVP_DecryptUpdate may overflow the output length argument in some cases where the input length is close to the maximum permissable length for an integer on the platform. In such cases the return value from the function call will be 1 (indicating success), but the output length value will be negative. This could cause applications to behave incorrectly or crash. OpenSSL versions 1.1.1i and below are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1j. OpenSSL versions 1.0.2x and below are affected by this issue. However OpenSSL 1.0.2 is out of support and no longer receiving public updates. Premium support customers of OpenSSL 1.0.2 should upgrade to 1.0.2y. Other users should upgrade to 1.1.1j. Fixed in OpenSSL 1.1.1j (Affected 1.1.1-1.1.1i). Fixed in OpenSSL 1.0.2y (Affected 1.0.2-1.0.2x).

CVSS 7.5 · HighBuzz score 17.5

Buzz score

Why this CVE is surfacing

Buzz score total 17.5

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 11.0 · diversity 6.5 · KEV 0.0 · OTX 0.0 · PoC 0.0
Mention score
11.0
2 evidence mentions in the snapshot
Diversity score
6.5
2 sources across 1 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
2 source links · newest first
  • The OpenSSL Project addressed three vulnerabilitiesSecurity Affairs

    The OpenSSL Project addressed three vulnerabilities, including two denial-of-service (DoS) issues and a bug in the SSLv2 rollback protection. The OpenSSL Project released security patches to address three vulnerabilities, two denial-of-service (DoS) flaws, and an incorrect SSLv2 rollback protection issue. The fist vulnerability, tracked as CVE-2021-23841, is a NULL pointer dereference issue that can be […]

    newssecurityaffairs.comFeb 18, 2021, 7:07 AM
  • Three New Vulnerabilities Patched in OpenSSLSecurityWeek

    The OpenSSL Project on Tuesday announced the availability of patches for three vulnerabilities, including two that can be exploited for denial-of-service (DoS) attacks and one related to incorrect SSLv2 rollback protection. The most serious of the vulnerabilities , with a severity rating of moderate , is CVE-2021-23841, a NULL pointer dereference issue that can result in a crash and a DoS condition. The security hole is related to a function (X509_issuer_and_serial_hash) that is never called directly by OpenSSL itself, which means it only impacts applications that use the function directly with certificates obtained from untrusted sources. The flaw was reported to OpenSSL developers by Google Project Zero researcher Tavis Ormandy and it has been patched with the release of OpenSSL 1.1.1j. Versions 1.1.1i and earlier are impacted. OpenSSL 1.1.1j also fixes a low-severity integer overflow issue that can also lead to a crash. The bug, tracked as CVE-2021-23840, was identified by Paul Keh…

    newswww.securityweek.comFeb 17, 2021, 9:31 AM

Exploit code

Public exploit repository references

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