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CVE mentions, exploit signals, and PoC evidence in one fast public view.

CVE detail

CVE-2021-3711

In order to decrypt SM2 encrypted data an application is expected to call the API function EVP_PKEY_decrypt(). Typically an application will call this function twice. The first time, on entry, the "out" parameter can be NULL and, on exit, the "outlen" parameter is populated with the buffer size required to hold the decrypted plaintext. The application can then allocate a sufficiently sized buffer and call EVP_PKEY_decrypt() again, but this time passing a non-NULL value for the "out" parameter. A bug in the implementation of the SM2 decryption code means that the calculation of the buffer size required to hold the plaintext returned by the first call to EVP_PKEY_decrypt() can be smaller than the actual size required by the second call. This can lead to a buffer overflow when EVP_PKEY_decrypt() is called by the application a second time with a buffer that is too small. A malicious attacker who is able present SM2 content for decryption to an application could cause attacker chosen data to overflow the buffer by up to a maximum of 62 bytes altering the contents of other data held after the buffer, possibly changing application behaviour or causing the application to crash. The location of the buffer is application dependent but is typically heap allocated. Fixed in OpenSSL 1.1.1l (Affected 1.1.1-1.1.1k).

CVSS 9.8 · CriticalBuzz score 26.0

Buzz score

Why this CVE is surfacing

Buzz score total 26.0

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 19.5 · diversity 6.5 · KEV 0.0 · OTX 0.0 · PoC 0.0
Mention score
19.5
6 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
6 source links · newest first
  • QNAP will patche OpenSSL flaws in its NAS devicesSecurity Affairs

    Network-attached storage (NAS) appliance maker QNAP is working on security patches for its products affected by recently fixed OpenSSL flaws. Taiwanese Network-attached storage (NAS) appliance maker QNAP announced that it is assessing the potential impact of two recently addressed flaws in OpenSSL on its products. The company also announced that it is working on security updates […]

    newssecurityaffairs.comSep 1, 2021, 6:36 PM
  • Companies Release Security Advisories in Response to New OpenSSL VulnerabilitiesSecurityWeek

    Companies that use OpenSSL in their products have started releasing security advisories to inform customers about the impact of two recently patched vulnerabilities. Updates announced by the OpenSSL Project on August 24 patched CVE-2021-3711, a high-severity buffer overflow related to SM2 decryption, and CVE-2021-3712, a medium-severity flaw that can be exploited for denial-of-service (DoS) attacks, and possibly for the disclosure of private memory contents. The high-severity vulnerability, patched with the release of OpenSSL 1.1.1l, can allow an attacker to change an application’s behavior or cause it to crash. The changes an attacker could make depend on the targeted app and the type of data it processes. Cybersecurity firm Sophos, which published an analysis of the two OpenSSL vulnerabilities , noted that an attacker could trick an application “into thinking that something succeeded (or failed) when it didn’t, or even to take over the flow of program execution entirely.” Several ma…

    newswww.securityweek.comAug 31, 2021, 10:44 AM
  • Security Affairs newsletter Round 329Security Affairs

    A new round of the weekly Security Affairs newsletter arrived! Every week the best security articles from Security Affairs free for you in your email box. If you want to also receive for free the international press subscribe here. EskyFun data leak, over 1 million Android gamers impacted Boffins show PIN bypass attack Mastercard and Maestro […]

    newssecurityaffairs.comAug 29, 2021, 8:19 AM
  • Some Synology products impacted by recently disclosed OpenSSL flawsSecurity Affairs

    Taiwan vendor Synology announced that recently disclosed vulnerabilities (CVE-2021-3711 and CVE-2021-3712) in the OpenSSL impact some of its products. Taiwanese company Synology revealed that the recently disclosed remote code execution (RCE) and denial-of-service (DoS) OpenSSL vulnerabilities (CVE-2021-3711 and CVE-2021-3712) impact some of its products. “Multiple vulnerabilities allow remote attackers to conduct denial-of-service attack or possibly execute arbitrary code via […]

    newssecurityaffairs.comAug 29, 2021, 7:01 AM
  • CVE-2021-3711 in OpenSSL can allow to change an application’s behaviorSecurity Affairs

    The OpenSSL Project patched a high-severity vulnerability, tracked as CVE-2021-3711, that can allow an attacker to change an application’s behavior or cause the app to crash. The OpenSSL Project released the OpenSSL 1.1.1l version that addresses a high-severity buffer overflow flaw, tracked as CVE-2021-3711, that could allow an attacker to change an application’s behavior or […]

    newssecurityaffairs.comAug 24, 2021, 9:43 PM
  • OpenSSL Vulnerability Can Be Exploited to Change Application DataSecurityWeek

    The OpenSSL Project on Tuesday announced the availability of OpenSSL 1.1.1l, which patches a high-severity vulnerability that could allow an attacker to change an application’s behavior or cause the app to crash. The flaw, tracked as CVE-2021-3711 , has been described as a buffer overflow related to SM2 decryption. “A malicious attacker who is able to present SM2 content for decryption to an application could cause attacker chosen data to overflow the buffer by up to a maximum of 62 bytes altering the contents of other data held after the buffer, possibly changing application behaviour or causing the application to crash. The location of the buffer is application dependent but is typically heap allocated,” the OpenSSL Project said in an advisory. The OpenSSL Project’s Matt Caswell told SecurityWeek that the changes an attacker could make depend on the targeted application and the type of data it holds in the heap immediately after the overrun buffer. “Think of any kind of data that an…

    newswww.securityweek.comAug 24, 2021, 3:44 PM

Exploit code

Public exploit repository references

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