Heap-based buffer overflow in Opera 7.11 and 7.20 allows remote attackers to execute arbitrary code via an HREF with a large number of esca…

published 2003-10-21 23 y ago modified 2026-06-16 4 mo ago also EUVD-2003-0860

cvss: 7.5; version 2.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 15.4%; EPSS 15.4% chance of exploitation in 30 days, percentile 96%
public exploits: 1; Exploit-DB

Heap-based buffer overflow in Opera 7.11 and 7.20 allows remote attackers to execute arbitrary code via an HREF with a large number of escaped characters in the server name.

Patch / fix

links 2

atstake.com/research/advisories/2003/a102003-1.txt advisory
securityfocus.com/bid/8853 advisory

Timeline

2003-10-20 First public exploit (EDB-23263)
2003-10-21 Published

Exploit prediction

15.43% chance of exploitation in the next 30 days, higher than 96% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

EDB-23263 Opera 7.11/7.20 HREF - Malformed Server Name Heap Corruption dos, 2003-10-20
atstake.com http://www.atstake.com/research/advisories/2003/a102003-1.txt referenced PoC, tagged "exploit" by a source, unverified
securityfocus.com http://www.securityfocus.com/bid/8853 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness

CWE-787 Out-of-bounds Write

References

atstake.com /research/advisories/2003/a102003-1.txt
vendor-advisory, exploit, patch
securityfocus.com /bid/8853
vdb-entry, broken-link, exploit, patch, third-party-advisory, vendor-advisory
exchange.xforce.ibmcloud.com /vulnerabilities/13458
vdb-entry, third-party-advisory
archives.neohapsis.com /archives/vulnwatch/2003-q4/0016.html
mailing-list, broken-link

Sources

CVE List CVE-2003-0870
NVD CVE-2003-0870

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary