GNU Wget through 1.25.0, fixed in commit dd692d9, contains a heap buffer overflow vulnerability in the htmlquotestring() function in src/convert.c that allows a remote attacker to trigger memory corruption by supplying a crafted HTML attribute with a large number of characters requiring entity encoding. A server-supplied HTML attribute causes a signed integer counter to overflow during output size accumulation, resulting in an undersized heap allocation and subsequent heap buffer overflow during the copy phase.

GNU Wget through 1.25.0, fixed in commit c2640fe, contains a heap buffer overflow vulnerability in the convertfname() function within src/url.c that allows remote attackers to trigger memory corruption through a server-supplied filename requiring character set conversion. When the output buffer is too small during iconv E2BIG reallocation, the reallocation logic miscalculates the remaining space, leading to a heap buffer overflow that can be exploited via a maliciously crafted server response.

GNU Wget through 1.25.0, fixed in commit 43d3ba9, contains an integer overflow vulnerability in the parsecontentrange() function within src/http.c that allows server-controlled values to cause signed integer arithmetic to overflow. Attackers can supply malicious Content-Range header values to trigger undefined behavior and download desynchronization in the affected client.