VulnerabilityPublished 27 Apr 2014Updated 29 May 2025

CVE-2014-1776: Microsoft Internet Explorer · Use After Free

Source CVE Database V5

Exploited in the wild · KEV due 28 Jul 2022 · 82% EPSS : apply the vendor's fix or mitigations to affected systems now.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

9.8Critical

How severe the flaw is on the 0–10 CVSS scale.

KEV deadline: 28 Jul 2022 US federal agencies must patch by this date; a sensible deadline for everyone else. Other KEV due dates
EPSS: 82.6% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 27 Apr 2014
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 7.8 years after disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

CVE ID reserved
by Microsoft Corporation
29 Jan 2014, 88 days before disclosure
CVE published
on cve.org
27 Apr 201410:00 UTC, t = 0
Added to CISA KEV (opens in a new tab)
exploitation confirmed
28 Jan 2022, 7.8 years after disclosure
KEV remediation due
US federal deadline
28 Jul 2022, 8.3 years after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Apply updates per vendor instructions.

Affected software

Product	Affected	Fixed in
n/a n/a	Affected 6 – 11 6 affected builds	Fixed in–

Description

Use-after-free vulnerability in Microsoft Internet Explorer 6 through 11 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via vectors related to the CMarkup::IsConnectedToPrimaryMarkup function, as exploited in the wild in April 2014. NOTE: this issue originally emphasized VGX.DLL, but Microsoft clarified that "VGX.DLL does not contain the vulnerable code leveraged in this exploit. Disabling VGX.DLL is an exploit-specific workaround that provides an immediate, effective workaround to help block known attacks."

Impact

For European organizations, the impact of CVE-2014-1776 can be substantial. Many enterprises and government agencies in Europe have historically used Internet Explorer as a default or legacy browser, especially in environments with legacy web applications or intranet portals. Exploitation could lead to remote code execution, enabling attackers to gain unauthorized access to sensitive data, deploy malware, or disrupt critical services. This is particularly concerning for sectors such as finance, healthcare, and public administration, where confidentiality and availability are paramount. Additionally, the vulnerability's ability to cause denial of service could interrupt business operations or critical infrastructure services. Given the lack of required user interaction and the ease of exploitation over the network, attackers could leverage this vulnerability to conduct targeted attacks or widespread campaigns. The risk is amplified in organizations that have not applied security patches or continue to use unsupported versions of Internet Explorer. Furthermore, the vulnerability could be used as a foothold for lateral movement within corporate networks, increasing the scope of compromise.

Mitigation

To mitigate CVE-2014-1776, European organizations should prioritize the following actions: 1) Apply all relevant Microsoft security patches released since April 2014 that address this vulnerability. 2) Disable or restrict the use of Internet Explorer, especially versions 6 through 11, in favor of modern, supported browsers with improved security architectures. 3) If Internet Explorer usage is unavoidable, implement application whitelisting and sandboxing to limit the impact of potential exploitation. 4) Disable VGX.DLL as an immediate workaround to block known exploit vectors, understanding that this is a temporary measure and not a substitute for patching. 5) Employ network-level protections such as web filtering and intrusion prevention systems configured to detect and block exploit attempts targeting this vulnerability. 6) Conduct user awareness training to discourage the use of outdated browsers and promote security best practices. 7) Regularly audit and update legacy systems and software dependencies to reduce exposure to unsupported software vulnerabilities. 8) Monitor network and endpoint logs for indicators of compromise related to Internet Explorer exploitation attempts.

CWE-416Use After Free (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #7
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Architecture and Design · Language Selection
Choose a language that provides automatic memory management.
Implementation · Attack Surface Reduction
When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

Timeline

What to do

Affected software

Description

AI analysisMachine-generated, updated 8 Jul 2025, 02:39 UTC

WeaknessesCWE-416

Technical details

References

Community reviews

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