VulnerabilityPublished 22 Sep 2025

CVE-2025-51006: Double Free

Source CVE Database V5

Not known to be exploited · CVSS 7.8 High.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score

7.8High

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
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: 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

Disclosed: evidence found.
CVE published 22 Sep 2025
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

AI-suggested

To mitigate this vulnerability, European organizations should first identify all systems where tcpreplay and specifically tcprewrite are installed and used. Immediate steps include restricting execution of tcprewrite to trusted administrators and users only, enforcing strict access controls on pcap files, and validating input files before processing. Organizations should monitor vendor advisories for patches or updates addressing this vulnerability and apply them promptly once available. In the interim, consider disabling or removing tcprewrite from production or critical systems if not essential. Additionally, implement application whitelisting and endpoint protection measures to prevent unauthorized execution of crafted pcap files. Security teams should audit and monitor logs for crashes or unusual behavior related to tcprewrite usage. Incorporating these tools into sandboxed or isolated environments can limit the impact of potential exploitation. Finally, educate users about the risks of processing untrusted pcap files and enforce policies to avoid handling files from unknown or unverified sources.

Description

Within tcpreplay's tcprewrite, a double free vulnerability has been identified in the dlt_linuxsll2_cleanup() function in plugins/dlt_linuxsll2/linuxsll2.c. This vulnerability is triggered when tcpedit_dlt_cleanup() indirectly invokes the cleanup routine multiple times on the same memory region. By supplying a specifically crafted pcap file to the tcprewrite binary, a local attacker can exploit this flaw to cause a Denial of Service (DoS) via memory corruption.

Impact

For European organizations, the primary impact of this vulnerability is operational disruption. Organizations that use tcpreplay tools for network testing, security research, or forensic investigations may experience service interruptions or crashes when processing maliciously crafted pcap files. This could delay incident response, network diagnostics, or security assessments. While the vulnerability does not appear to allow privilege escalation or remote code execution, the DoS condition could be leveraged by an insider or attacker with local access to degrade system availability. In environments where tcpreplay is integrated into automated workflows or continuous security validation pipelines, this vulnerability could cause cascading failures or impact the reliability of network security controls. The risk is heightened in organizations with less stringent access controls or where untrusted users have the ability to execute tcprewrite. However, the lack of remote exploitability limits the threat to local or internal actors rather than external attackers.

CWE-415Double Free (opens in a new tab)
Variant weaknessLikelihood of exploit: High
The product calls free() twice on the same memory address.
Architecture and Design
Choose a language that provides automatic memory management.
Implementation
Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly.
Implementation
Use a static analysis tool to find double free instances.
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

Description

AI analysisMachine-generated, updated 22 Sep 2025, 13:48 UTC

WeaknessesCWE-415

Technical details

References

Community reviews

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