Threats / F5 / CVE-2020-5902
CVE-2020-5902
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-16
F5 BIG-IP vulnerability
F5 BIG-IP Traffic Management User Interface contains a remote code execution vulnerability in undisclosed pages, exploitable without authentication.
Verdict
Today item, not a backlog item.
Critical remote code execution in F5 BIG-IP TMUI allows unauthenticated attackers to execute arbitrary code. The vulnerability has been actively exploited in the wild and leveraged in ransomware campaigns.
CISA KEV Yes · 2021-11-033Ransomware use Flagged3EPSS 0.99999 (verify live)4Exploit Weaponized · public PoC5
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
832 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.99999 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: F5, BIG-IP. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-22 Path Traversal — weakness family: Path traversal / file.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No threat-actor attribution is established from the public feed for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I identify the F5 BIG-IP TMUI as internet-exposed and accessible without credentials.
Business
Perimeter security fails to prevent unauthorized access to critical load balancing infrastructure.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I exploit the path traversal vulnerability to reach undisclosed TMUI pages and execute arbitrary code.
Business
Complete compromise of BIG-IP systems enables lateral movement into protected networks and data exfiltration.
3
Lateral reach — past segmentation narrative 3
Attacker
I establish persistent access and deploy ransomware across dependent systems.
Business
Ransomware encryption of critical infrastructure causes operational shutdown and financial extortion.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05
Coverage & confidence
— what we know, and what we don’tEstablished (cited)
Coverage gaps — stated, not hidden
Disclosure & credit2
Catalogued by f5CNA
Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.