009-cve-2016-9844-zipinfo-buffer-overflow.patch (1125B)
1 From: "Steven M. Schweda" <sms@antinode.info> 2 Subject: Fix CVE-2016-9844, buffer overflow in zipinfo 3 Bug-Debian: https://bugs.debian.org/847486 4 Bug-Ubuntu: https://launchpad.net/bugs/1643750 5 X-Debian-version: 6.0-21 6 7 --- a/zipinfo.c 8 +++ b/zipinfo.c 9 @@ -1921,7 +1921,18 @@ static int zi_short(__G) /* return PK- 10 ush dnum=(ush)((G.crec.general_purpose_bit_flag>>1) & 3); 11 methbuf[3] = dtype[dnum]; 12 } else if (methnum >= NUM_METHODS) { /* unknown */ 13 - sprintf(&methbuf[1], "%03u", G.crec.compression_method); 14 + /* 2016-12-05 SMS. 15 + * https://launchpad.net/bugs/1643750 16 + * Unexpectedly large compression methods overflow 17 + * &methbuf[]. Use the old, three-digit decimal format 18 + * for values which fit. Otherwise, sacrifice the "u", 19 + * and use four-digit hexadecimal. 20 + */ 21 + if (G.crec.compression_method <= 999) { 22 + sprintf( &methbuf[ 1], "%03u", G.crec.compression_method); 23 + } else { 24 + sprintf( &methbuf[ 0], "%04X", G.crec.compression_method); 25 + } 26 } 27 28 for (k = 0; k < 15; ++k)