Listen to this Post
How CVE-2025-26311 Works:
The vulnerability exists in libming v0.4.8’s SWF file parsing functionality. When processing Clip Actions in SWF files (specifically in parseSWF_CLIPACTIONS and parseSWF_CLIPACTIONRECORD functions within util/parser.c), the library fails to properly release allocated memory. Attackers can craft malicious SWF files containing specially designed Clip Actions that trigger repeated memory allocations without corresponding deallocations. This leads to memory exhaustion and eventual denial-of-service conditions. The flaw occurs during SWF parsing where the library doesn’t implement proper memory cleanup for nested ClipActionRecord structures, allowing gradual memory consumption until system resources are depleted.
DailyCVE Form:
Platform: libming
Version: 0.4.8
Vulnerability: Memory leak
Severity: Critical
Date: 2025-02-20
What Undercode Say:
// Vulnerable code snippet (simplified)
void parseSWF_CLIPACTIONS(SWF swf) {
CLIPACTIONS actions = malloc(sizeof(CLIPACTIONS));
while(hasMoreActions()) {
CLIPACTIONRECORD rec = parseSWF_CLIPACTIONRECORD();
// Missing: free(rec) after processing
}
// Missing: free(actions)
}
Exploit PoC generation
python -c 'print("FWS" + "\x00\x00\x00\x01" + "\x00\x00\x00" + "CLIPACTIONS"10000)' > exploit.swf
// Patch example
void parseSWF_CLIPACTIONS(SWF swf) {
CLIPACTIONS actions = malloc(sizeof(CLIPACTIONS));
while(hasMoreActions()) {
CLIPACTIONRECORD rec = parseSWF_CLIPACTIONRECORD();
processAction(rec);
free(rec); // Added cleanup
}
free(actions); // Added cleanup
}
Detection command strings -n 10 malicious.swf | grep -q "CLIPACTIONS" && echo "Potential exploit"
Memory monitoring script
import psutil
while True:
mem = psutil.virtual_memory()
if mem.percent > 90:
print("Memory exhaustion detected!")
kill_process("ming")
// Safe coding pattern
define SAFE_FREE(p) do { if(p) { free(p); p=NULL; } } while(0)
Mitigation (temporary) sysctl -w vm.overcommit_memory=2 ulimit -v 500000
SWF file validator
def validate_swf(file):
if file.count(b"CLIPACTIONS") > 100:
raise Exception("Suspicious SWF")
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
