CVE-2021-27247: tencent wechat Out-of-bounds Read
Vulnerability summary
CVE-2021-27247 is a medium (CVSS 6.5) Out-of-bounds Read vulnerability in tencent wechat. EPSS estimates a 6.67% chance of exploitation in the next 30 days, higher than 93.9% of scored vulnerabilities.
Not severe (CVSS 6.5, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Timeline
- 14-04-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
This vulnerability allows remote attackers to disclose sensitive information on affected installations of Tencent WeChat 2.9.5 desktop version. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the WXAM decoder. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated buffer. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of the current process. Was ZDI-CAN-11907.
CVSS metrics
4 scores · 2 sources · 3 versions- NVDNIST6.5MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
EPSS trend
Probability
6.67%
Chance of exploitation in the next 30 days
Percentile
94%
Versus all other CVEs
30-day change
Increase +0.23 pp
From 6.45% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.
Tencent1 product
- wechat2.9.5 desktop version | 2.9.5
1 vendor · 1 product