Evidence used
- No CISA KEV confirmation is currently recorded.
- A structured source references public exploit or proof-of-concept material.
- EPSS is 1.04% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2023
CVE-2021-33974High confidence
Qihoo 360 (https://www.360.cn/) Qihoo 360 Safeguard (https://www.360.cn/) Qihoo 360 Chrome (https://browser.360.cn/ee/) is affected by: Buffer Overflow
Unknown · Unknown
8.8HighCVSS 3.1
Within 7 days
Fix not verifiedHigh technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:Critical, raised one band.upgradedsince 5 Feb 2025
Compensating controls
- Restrict the affected network interface to trusted sources where business-safe.
- Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
- Confirm that the asset runs Unknown Unknown and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Fix not verified01
What, why and how
Qihoo 360 (https://www.360.cn/) Qihoo 360 Safeguard (https://www.360.cn/) Qihoo 360 Chrome (https://browser.360.cn/ee/) is affected by: Buffer Overflow. The impact is: execute arbitrary code (remote). The component is: This is a set of vulnerabilities affecting popular software, and the installation packages correspond to versions "360 Safeguard(12.1.0.1004,12.1.0.1005,13.1.0.1001)" , "360 Total Security(10.8.0.1060,10.8.0.1213)", "360 Safe Browser & 360 Chrome(12. The attack vector is: On the browser vulnerability, just open a link to complete the vulnerability exploitation remotely; on the client software, you need to locally execute the vulnerability exploitation program, which of course can be achieved with the full chain of browser vulnerability. ¶¶ This is a set of the most serious vulnerabilities that exist on Qihoo 360's PC client multiple popular software, remote vulnerabilities can be accomplished by opening a link to arbitrary code execution on both security browsers, in conjunction with the exploitation of local vulnerabilities that allow spyware to persist without being scanned to permanently reside on the target PC computer (because local vulnerabilities target Qihoo 360 company's antivirus software kernel flaws); this set of remote and local vulnerabilities in perfect coordination, to achieve an information security fallacy, on Qihoo 360's antivirus software vulnerability, not only can not be scanned out of the virus, but will help the virus persistently control the target computer, while Qihoo 360 claims to be a secure browser, which exists in the kernel vulnerability but help the composition of the remote vulnerability.(Security expert "Memory Corruptor" have reported this set of vulnerabilities to the corresponding vendor, all vulnerabilities have been fixed and the vendor rewarded thousands of dollars to this security expert)
What
Qihoo 360 (https://www.360.cn/) Qihoo 360 Safeguard (https://www.360.cn/) Qihoo 360 Chrome (https://browser.360.cn/ee/) is affected by: Buffer Overflow. The impact is: execute arbitrary code (remote). The component is: This is a set of vulnerabilities affecting popular software, and the installation packages correspond to versions "360 Safeguard(12.1.0.1004,12.1.0.1005,13.1.0.1001)" , "360 Total Security(10.8.0.1060,10.8.0.1213)", "360 Safe Browser & 360 Chrome(12. The attack vector is: On the browser vulnerability, just open a link to complete the vulnerability exploitation remotely; on the client software, you need to locally execute the vulnerability exploitation program, which of course can be achieved with the full chain of browser vulnerability. ¶¶ This is a set of the most serious vulnerabilities that exist on Qihoo 360's PC client multiple popular software, remote vulnerabilities can be accomplished by opening a link to arbitrary code execution on both security browsers, in conjunction with the exploitation of local vulnerabilities that allow spyware to persist without being scanned to permanently reside on the target PC computer (because local vulnerabilities target Qihoo 360 company's antivirus software kernel flaws); this set of remote and local vulnerabilities in perfect coordination, to achieve an information security fallacy, on Qihoo 360's antivirus software vulnerability, not only can not be scanned out of the virus, but will help the virus persistently control the target computer, while Qihoo 360 claims to be a secure browser, which exists in the kernel vulnerability but help the composition of the remote vulnerability.(Security expert "Memory Corruptor" have reported this set of vulnerabilities to the corresponding vendor, all vulnerabilities have been fixed and the vendor rewarded thousands of dollars to this security expert)
Why
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
How
An attacker operating through a network path may attempt exploitation without authentication after a user interaction. If successful, the issue may execute code or commands in the affected security context.
What
Qihoo 360 (https://www.360.cn/) Qihoo 360 Safeguard (https://www.360.cn/) Qihoo 360 Chrome (https://browser.360.cn/ee/) is affected by: Buffer Overflow. The impact is: execute arbitrary code (remote). The component is: This is a set of vulnerabilities affecting popular software, and the installation packages correspond to versions "360 Safeguard(12.1.0.1004,12.1.0.1005,13.1.0.1001)" , "360 Total Security(10.8.0.1060,10.8.0.1213)", "360 Safe Browser & 360 Chrome(12. The attack vector is: On the browser vulnerability, just open a link to complete the vulnerability exploitation remotely; on the client software, you need to locally execute the vulnerability exploitation program, which of course can be achieved with the full chain of browser vulnerability. ¶¶ This is a set of the most serious vulnerabilities that exist on Qihoo 360's PC client multiple popular software, remote vulnerabilities can be accomplished by opening a link to arbitrary code execution on both security browsers, in conjunction with the exploitation of local vulnerabilities that allow spyware to persist without being scanned to permanently reside on the target PC computer (because local vulnerabilities target Qihoo 360 company's antivirus software kernel flaws); this set of remote and local vulnerabilities in perfect coordination, to achieve an information security fallacy, on Qihoo 360's antivirus software vulnerability, not only can not be scanned out of the virus, but will help the virus persistently control the target computer, while Qihoo 360 claims to be a secure browser, which exists in the kernel vulnerability but help the composition of the remote vulnerability.(Security expert "Memory Corruptor" have reported this set of vulnerabilities to the corresponding vendor, all vulnerabilities have been fixed and the vendor rewarded thousands of dollars to this security expert)
Why
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
How
An attacker operating through a network path may attempt exploitation without authentication after a user interaction. If successful, the issue may execute code or commands in the affected security context.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material Reference recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.
- Likely attack path
- a network path → Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') → execute code or commands in the affected security context
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- Required interaction required
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-120 ↗
CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow'). The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Fix not verified
- Affected
- n/a
- Fixed
- No fixed version is explicitly recorded in the structured CVE data.
- Action
- No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 19 Apr 2023 · Last source change 5 Feb 2025, 16:04 UTC · CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2021-20645
Product sourceUnavailable
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
NVD statusNVD modified after enrichment
Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.