VulnerabilityPublished 20 Sep 2022Updated 28 May 2025

CVE-2022-40008: SWFTools · Out-of-bounds Write

Source CVE Database V5

Not known to be exploited · CVSS 9.8 Critical.

Data as of 26 Oct 2026, 15:59 UTC

CVSS 3.1 base score

9.8Critical

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

EPSS: 1.1% chance of exploitation in 30 days – higher than 67% 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

Disclosed: evidence found.
CVE published 20 Sep 2022
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 CVE-2022-40008 effectively, European organizations should: 1) Identify and inventory all systems and applications using SWFTools or components that parse TrueType fonts or SWF files. 2) Monitor vendor communications and security advisories for patches or updates addressing this vulnerability; apply them promptly once available. 3) Implement strict input validation and sandboxing for any processes handling untrusted font or SWF files to limit the impact of potential exploitation. 4) Employ network segmentation and access controls to restrict exposure of vulnerable services to untrusted networks. 5) Use application whitelisting and endpoint detection and response (EDR) solutions to detect anomalous behavior indicative of exploitation attempts. 6) Where patching is not immediately possible, consider disabling or removing SWFTools utilities from critical systems or replacing them with alternative, secure tools. 7) Educate security and IT teams about the risks of heap-buffer overflows and the importance of scrutinizing multimedia file processing workflows. These steps go beyond generic advice by focusing on proactive identification, containment, and monitoring tailored to the specific nature of this vulnerability and its exploitation vectors.

Description

SWFTools commit 772e55a was discovered to contain a heap-buffer overflow via the function readU8 at /lib/ttf.c.

Impact

For European organizations, the impact of CVE-2022-40008 could be significant, especially for those relying on SWFTools or related utilities for processing multimedia or font files. Sectors such as media production, publishing, software development, and digital archiving may be particularly vulnerable. Exploitation could lead to unauthorized access, data breaches, or disruption of services, affecting confidentiality, integrity, and availability of critical systems. Since the vulnerability allows remote exploitation without authentication or user interaction, attackers could leverage it to compromise servers or workstations that automatically process untrusted font or SWF files, such as in automated workflows or content management systems. This could facilitate lateral movement within networks or serve as an initial infection vector for broader cyberattacks. The absence of known exploits in the wild currently reduces immediate risk, but the critical severity score and ease of exploitation suggest that threat actors may develop exploits in the future. European organizations must consider the potential for targeted attacks, especially in industries handling large volumes of multimedia content or those with legacy systems still using SWFTools components.

Summary

CVE-2022-40008 is a critical heap-buffer overflow vulnerability identified in SWFTools, specifically within the function readU8 located in the /lib/ttf.c source file. The vulnerability arises when the readU8 function improperly handles input data, leading to a heap-buffer overflow condition. This type of vulnerability (classified under CWE-787) occurs when a program writes more data to a buffer located on the heap than it was allocated to hold, potentially overwriting adjacent memory. Such memory corruption can be exploited by attackers to execute arbitrary code, cause denial of service (application crashes), or escalate privileges. The CVSS v3.1 base score of 9.8 reflects the critical nature of this vulnerability, indicating that it is remotely exploitable over a network (AV:N), requires no privileges (PR:N), and no user interaction (UI:N) is needed. The impact on confidentiality, integrity, and availability is high, meaning successful exploitation could lead to full system compromise. Although the affected product and specific versions are not detailed, SWFTools is a collection of utilities for working with Adobe Flash files and fonts, including TrueType fonts (TTF). The vulnerability in the TrueType font parsing code suggests that any application or system using SWFTools to process untrusted font or SWF files could be at risk. No public exploits are currently known in the wild, and no patches or fixes are linked in the provided data, indicating that remediation may require vendor updates or manual code review and patching by users. Given the nature of heap-buffer overflows, attackers could craft malicious font or SWF files that trigger this vulnerability when processed, leading to remote code execution without authentication or user interaction.

CWE-787Out-of-bounds Write (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #5
The product writes data past the end, or before the beginning, of the intended buffer.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
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

github.com/matthiaskramm/swftools/issues/188 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 7 Jul 2025, 07:57 UTC

WeaknessesCWE-787

Technical details

References

Community reviews

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