VulnerabilityPublished 30 Jun 2016Updated 9 Jun 2025

CVE-2016-3189: Use After Free

Source CVE Database V5

Not known to be exploited · 15% EPSS · CVSS 6.5 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 15.5% chance of exploitation in 30 days – higher than 96% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: None
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: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
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: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within 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

Disclosed: evidence found.
CVE published 30 Jun 2016
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: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (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

Affected software

Product	Affected	Fixed in
n/a n/a	Affected =1.0.6	Fixed in–

AI-suggested

To mitigate this vulnerability, European organizations should first verify if bzip2recover version 1.0.6 or earlier is in use within their environments. Upgrading to the latest version of bzip2, where this vulnerability is patched, is the most effective measure. If upgrading is not immediately possible, organizations should implement strict input validation and restrict the processing of bzip2 archives from untrusted or unauthenticated sources. Employ sandboxing or containerization techniques to isolate the bzip2recover process, limiting the impact of potential crashes. Monitoring and alerting on abnormal termination of bzip2recover can help detect exploitation attempts. Additionally, educating users about the risks of opening or processing untrusted compressed files can reduce the likelihood of user interaction-based exploitation. For automated systems, incorporating integrity checks and scanning compressed files for anomalies before processing can further reduce risk. Finally, applying general memory protection mechanisms such as Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP) on systems running bzip2recover can help mitigate exploitation attempts that might escalate beyond denial of service.

Description

Use-after-free vulnerability in bzip2recover in bzip2 1.0.6 allows remote attackers to cause a denial of service (crash) via a crafted bzip2 file, related to block ends set to before the start of the block.

Impact

For European organizations, the primary impact of CVE-2016-3189 is the potential for denial of service attacks against systems that utilize bzip2recover for data recovery from bzip2 archives. This could disrupt automated backup restoration processes, data recovery workflows, or any service relying on bzip2recover to handle compressed data. While the vulnerability does not directly compromise data confidentiality or integrity, the availability impact could affect operational continuity, especially in environments where bzip2 is integrated into critical data processing pipelines. Organizations with automated systems that decompress or recover bzip2 archives from untrusted sources are at higher risk. The requirement for user interaction means that exploitation typically involves a user triggering the processing of a malicious file, which could occur via phishing or malicious file delivery. Given that bzip2 is widely used in Linux and Unix-like environments, including many servers and embedded systems across Europe, the risk is non-negligible. However, the lack of known exploits and the medium severity rating suggest that the threat is moderate rather than critical. Nonetheless, disruption of services due to crashes could have cascading effects in sectors such as finance, healthcare, and government services that rely on stable data recovery operations.

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

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Jul 2025, 21:31 UTC

WeaknessesCWE-416

Technical details

References

Community reviews

Related threats