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Threats / Telerik / CVE-2017-11317
CVE-2017-11317 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Telerik User Interface (UI) for ASP.NET AJAX vulnerability

Telerik UI for ASP.NET AJAX contains a weak cryptography vulnerability enabling remote attackers to upload arbitrary files or execute code without authentication.

Verdict

Today item — known-exploited.

A remote attacker can exploit insufficient cryptographic protections in Telerik.Web.UI to bypass file upload restrictions and achieve arbitrary code execution on affected ASP.NET AJAX applications. Active exploitation in the wild increases risk.

CISA KEV Yes · 2022-04-113EPSS 0.83476 (verify live)4Exploit Weaponized · public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit 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
11 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 2022-04-11).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.83476 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Telerik, User Interface (UI) for ASP.NET AJAX. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-326 Inadequate Encryption Strength — weakness family: Cryptography.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution not established

No confirmed (advisory-backed) threat-actor attribution is established 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 board
1

Front door — unauthenticated access narrative 1

Attacker
I identify that the application uses Telerik UI for ASP.NET AJAX with weak cryptographic controls protecting file upload operations.
Business
The organization runs vulnerable Telerik components in production without compensating controls or timely patching.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I craft a malicious file upload request that bypasses the cryptographic validation due to insufficient key strength or algorithm weakness.
Business
Attackers actively exploit this vulnerability in the wild, creating immediate compromise risk across unpatched deployments.
3

Lateral reach — past segmentation narrative 3

Attacker
I upload a web shell or malicious executable to the server, gaining remote code execution capabilities on the host.
Business
The compromised server becomes a foothold for lateral movement, data exfiltration, and potential ransomware deployment within the network.
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’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • Weaponized exploit available (VulnCheck)
  • 11 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • Catalogued by mitre (CNA)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
  • Disclosure & credit2
    Catalogued by mitreCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.