Buffer overflow in APNGDis 2.8 and earlier allows remote attackers to cause a denial of service and possibly execute arbitrary code via a crafted image containing a malformed image size descriptor in the IHDR chunk.
In plain language
Written by AI from the record
CVE-2017-6193 is a flaw in an APNG disassembler that can crash the app (and possibly run code) when it opens a specially crafted image; if you run APNGDis yourself, you should take action, but many small businesses won’t be affected unless they process untrusted images with that tool.
CVE-2017-6193 is a buffer overflow in APNGDis (2.8 and earlier) triggered by a malformed image size descriptor inside the IHDR chunk of a crafted APNG, leading to denial of service and potentially arbitrary code execution; public exploitation exists.
If you're affected
Application crash while processing images
Possible arbitrary code execution
Operational disruption from repeated crashes
Risk from malicious image uploads
What is it
This bug is like a flaw in a tool’s way of reading certain PNG animation images. If someone gives it a deliberately weird image, the tool can crash, and in worse cases it could be tricked into doing unsafe actions instead of just reading the image. Think of it as a doorstop that breaks when hit with a specially shaped key.
Who is affected
This matters if your business runs the "apng disassembler" (APNGDis) to parse APNG images—especially images from customers, the public internet, or other untrusted sources. Many businesses aren’t affected if they never use this specific tool. The risk is mainly if a malicious image can reach APNGDis (for example, via uploads or files you accept from others) and APNGDis is 2.8 or earlier.
How urgent is it
Treat this as urgent to act on internally because public exploits are available and the flaw can be triggered by simply opening a crafted image. The fix details are not available in the provided information, so you should prioritize reducing exposure (stop untrusted inputs) until you can replace/upgrade the tool. With no KEV listing and only predicted likelihood, the timing depends on whether your workflows feed untrusted images to APNGDis—but if they do, act now.
What to do — in detail
Confirm whether you’re exposed
Identify where APNGDis is installed and what version you run (your process, file-handling scripts, or server image pipeline may include it).
Confirm input sources:
Do you open/convert APNG files received from customers/users?
Do you process images from websites, email attachments, chats, or third-party feeds?
If all APNG input is fully trusted and controlled, exposure may be lower.
Match against the affected versions
This issue affects APNGDis 2.8 and earlier.
If you are on 2.8 or earlier, assume the tool can be crashed and possibly exploited when parsing a crafted image.
Patch / upgrade plan
The provided findings say no fix/patch information is available, so there isn’t a clearly documented “upgrade to X.Y.Z” path from this data.
Practical remediation:
Replace APNGDis with an alternative image-processing tool that you can patch/verify.
If replacement is not immediate, remove APNGDis from the path for untrusted images.
Temporary workarounds (when you can’t upgrade right away)
Restrict untrusted inputs: block or limit who can upload images, and require authentication for any upload feature.
Pre-validate images: run images through a separate, safer checker/converter first, and only process outputs that pass strict validation.
Fail safely: ensure crashes don’t take down the whole service (for example, isolate the image-processing step into a controlled process/container).
Detection and monitoring
Review logs for crashes or repeated failures when handling APNG files.
Watch for evidence of image-processing jobs failing during or right after handling externally supplied images.
If feasible, capture the crafted inputs that cause failures (for internal analysis) and block those patterns at your upload/processing layer.
KEV timeline
CISA KEV does not list this vulnerability (per the findings), so there is no stated KEV-driven due date from the provided data.
Technical context
CVE-2017-6193 describes a buffer overflow (CWE-119) in APNGDis when parsing APNG images. The failure is triggered by a malformed image size descriptor inside the IHDR chunk. Impact includes denial of service (crash) and possibly arbitrary code execution.
Exploitation status: the findings indicate public exploitation exists (“public exploit available” with known exploit instances). KEV is not listed, and predicted likelihood is provided as a flat trend (but this is not treated as proof of exploitation for urgency decisions).
Risk framing for businesses: if your environment allows an attacker to supply a crafted APNG to a vulnerable APNGDis instance (2.8 or earlier), the attacker can cause a crash reliably and may be able to escalate to code execution depending on runtime and build conditions. Patch information was not provided in the findings, so mitigation should focus on removing untrusted inputs from APNGDis and replacing the tool or isolating its execution.
This is a general assessment based on public vulnerability data. It does not account for your specific infrastructure — when in doubt, consult a security specialist.
